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High brightness LEDs?
These LED replacements for 240V mains lamps; if one were to
open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? |
High brightness LEDs?
gareth wrote:
These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? You might find a little constant current supply, but my guess is that you'd just find a big dropping resistor. That configuration would result in most of the power being wasted as heat, but it would still produce less heat than an incandescent and be brighter. If you want a high voltage regulator, a TIP50 transistor and a high voltage zener (or a string of low voltage zeners) will fix you right up. The TIP50 is comparatively easy to damage, but if you don't hook it up backwards or something it will be very, very reliable. Not expensive. Think of the TIP50 as a 5080 replacement with a lot more gain and better transconductance in the bargain. If you want a high voltage switcher, on the other hand, look at the Linear Technology chips intended for LCD backlight inverters. There are some great Jim Williams applications notes. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
High brightness LEDs?
On 11/28/2014 8:50 AM, Scott Dorsey wrote:
gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? You might find a little constant current supply, but my guess is that you'd just find a big dropping resistor. That configuration would result in most of the power being wasted as heat, but it would still produce less heat than an incandescent and be brighter. If you want a high voltage regulator, a TIP50 transistor and a high voltage zener (or a string of low voltage zeners) will fix you right up. The TIP50 is comparatively easy to damage, but if you don't hook it up backwards or something it will be very, very reliable. Not expensive. Think of the TIP50 as a 5080 replacement with a lot more gain and better transconductance in the bargain. If you want a high voltage switcher, on the other hand, look at the Linear Technology chips intended for LCD backlight inverters. There are some great Jim Williams applications notes. --scott No, these have electronic power supplies in them. Otherwise they would dissipate huge amounts of heat. Think about it. LED's run at about 3V. That means a 9W LED requires about 3 amps of power. 3 amps at 240V is 720W - or about 711W of power wasted. They would be way less efficient than any other type of bulbs. Plus LED's run on DC and would not work as efficiently on 50Hz AC. However, they also are generally pretty well potted and almost impossible to take apart without destroying them. And even if you could get one apart, its design is single-purpose and generally won't do well in a different application. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
In rec.radio.amateur.boatanchors gareth wrote:
These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? -- Jim Pennino |
High brightness LEDs?
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High brightness LEDs?
In rec.radio.amateur.boatanchors Michael Black wrote:
On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Of course, one can run tubes on low voltage. The Collins 75S receiver line apparently kept plat voltage relatively low (somewhere around 120v if I remember right) which had certain advantages. One can run regular tubes at 12VDC on the plate, there were some articles in Popular Electronics about this, calling them "starved circuits". Or there were those tubes designed to run off 12VDC for those hybrid car radios, a last gasp before transistors took over completely. Though, 3VDC does seem a tad low. When they were running regular tubes on "low voltage", that was voltages around 100 V as opposed to 200 to 300 Volts. The 12 Volt tubes are long gone and not that great to begin with. Michael -- Jim Pennino |
High brightness LEDs?
On Fri, 28 Nov 2014 15:00:46 -0500, Michael Black
wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. Of course, one can run tubes on low voltage. The Collins 75S receiver line apparently kept plat voltage relatively low (somewhere around 120v if I remember right) which had certain advantages. One can run regular tubes at 12VDC on the plate, there were some articles in Popular Electronics about this, calling them "starved circuits". Or there were those tubes designed to run off 12VDC for those hybrid car radios, a last gasp before transistors took over completely. I had a hybrid car radio with four valves and two transistors. The RF amp, mixer, IF amp, and first audio used valves. Those valves had 12 volts on the plate. I also had a valve test oscillator that ran off a 9 volt grid bias battery. Though, 3VDC does seem a tad low. Michael -- Judge John E. Jones wrote: To be sure, Darwin’s theory of evolution is imperfect. However, the fact that a scientific theory cannot yet render an explanation on every point should not be used as a pretext to thrust an untestable alternative hypothesis grounded in religion into the science classroom or to misrepresent well-established scientific propositions. When faith comes in logic goes out |
High brightness LEDs?
In rec.radio.amateur.boatanchors Jerry Stuckle wrote:
On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. -- Jim Pennino |
High brightness LEDs?
On Fri, 28 Nov 2014 08:50:09 -0500, Scott Dorsey wrote:
gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? You might find a little constant current supply, but my guess is that you'd just find a big dropping resistor. That configuration would result in most of the power being wasted as heat, but it would still produce less heat than an incandescent and be brighter. If you want a high voltage regulator, a TIP50 transistor and a high voltage zener (or a string of low voltage zeners) will fix you right up. The TIP50 is comparatively easy to damage, but if you don't hook it up backwards or something it will be very, very reliable. Not expensive. Think of the TIP50 as a 5080 replacement with a lot more gain and better transconductance in the bargain. If you want a high voltage switcher, on the other hand, look at the Linear Technology chips intended for LCD backlight inverters. There are some great Jim Williams applications notes. --scott The regulators in LED lamps are constant current types, not constant voltage. They also have some sort of step-down circuit because the LED needs a lot more current than what you would want to draw from the AC lines. Common power LED currents are in the neighborhood of 350 and 700 mA. Some very small LED lamps, Christmas light size, use capacitors to limit the current. Jim Mueller -- Jim Mueller To get my real email address, replace wrongname with dadoheadman. Then replace nospam with fastmail. Lastly, replace com with us. |
High brightness LEDs?
On 11/28/2014 5:24 PM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/28/2014 6:16 PM, Jerry Stuckle wrote:
On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Jerry says, Then why can't you use standard incandescent dimmers with LED bulbs? Which is wrong because you can use "standard" dimmers, but the LED bulb has to be designed for it. Try reading a little... http://www.ledsmagazine.com/articles...-magazine.html -- Rick |
High brightness LEDs?
In rec.radio.amateur.boatanchors Jerry Stuckle wrote:
On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? Yes, for LED bulbs. However, the simplest way to see that the light output is controlled by the applied voltage is to simply look at the base of a dimmable bulb and note that there are only two connections; no third connection for a control, just the same as all other light bulbs. Some are dimmable and some are not because it takes more parts to make a dimmable bulb and the demand for them is less than that for non-dimmable bulbs. To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. Nope; light bulbs run at a rated voltage which is the standard voltage for the country in which they are sold; US light bulbs are rated for 120v, UK bulbs for whatever the voltage is over there, I think 240V. You are just arguing for the sake of arguing. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? You can if the bulb is specified as dimmable; some are, and some are not and they all use the standard two connection E26 base. A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. None of this has anything to do with high voltage. The standard US wall outlet is rated at 15 Amps. A Phillips A21 75W replacement LED bulb draws 15W at 120V (0.125A) and is dimmable. http://www.usa.philips.com/c-p/04667...white-dimmable You obviously are unfamiliar with the structure of LED bulbs. You obiously have never noticed that the base of an LED bulb is identical to that of an incandescent, i.e. two wire E26 base, and that standard wall outlets in the US are 15 Amps. -- Jim Pennino |
High brightness LEDs?
In rec.radio.amateur.boatanchors rickman wrote:
On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: snip Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, No, I am NOT speculating on anything. You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Yes, it is correct as it means that the average voltage is changed. Incandescent bulbs are thermal devices and the light ouput is directly proportional to the average applied voltage and don't care if the applied voltage is DC, a sine wave, or pulses derived from a sine wave. And dimmers do NOT work by changing the phase angle, they work by changing a thyristor phase control. See: http://en.wikipedia.org/wiki/Thyristor#Applications -- Jim Pennino |
High brightness LEDs?
On 11/28/2014 7:37 PM, wrote:
In rec.radio.amateur.boatanchors rickman wrote: On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: snip Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, No, I am NOT speculating on anything. You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Yes, it is correct as it means that the average voltage is changed. Incandescent bulbs are thermal devices and the light ouput is directly proportional to the average applied voltage and don't care if the applied voltage is DC, a sine wave, or pulses derived from a sine wave. And dimmers do NOT work by changing the phase angle, they work by changing a thyristor phase control. See: http://en.wikipedia.org/wiki/Thyristor#Applications Please be as pedantic as you like. You are wrong. The very article you reference shows that the dimmer works by controlling the phase angle over which the AC voltage is passed to the load. There are *many* LED bulbs which can be dimmed by this standard type of dimmer. As the reference I provide shows, these bulbs include smarts to measure this phase angle and adjust the bulb brightness accordingly. I have several in my home. -- Rick |
High brightness LEDs?
In rec.radio.amateur.boatanchors rickman wrote:
On 11/28/2014 7:37 PM, wrote: snip See: http://en.wikipedia.org/wiki/Thyristor#Applications Please be as pedantic as you like. You are wrong. No, I am not, and I am being precise in my language. The very article you reference shows that the dimmer works by controlling the phase angle over which the AC voltage is passed to the load. Which is the phase angle, or more properly, the conduction angle of the contolling device, not the phase angle of the AC source. If the voltage is turned off for part of the conduction cycle, the average voltage changes. This is Electronics 101. There are *many* LED bulbs which can be dimmed by this standard type of dimmer. Yes, there are, but that is irrelevant to how a dimmer works and only relevant to how the bulb works. As the reference I provide shows, What reference? these bulbs include smarts to measure this phase angle You mean conduction angle? You can't measure a phase angle absent a reference signal of a known phase. Again, Electronic 101. and adjust the bulb brightness accordingly. I have several in my home. Whoopee!! -- Jim Pennino |
High brightness LEDs?
On 11/28/2014 7:05 PM, rickman wrote:
On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, Sorry, but lighting control has been my job for much of the last 11 years. I am considered an expert in it by many of my peers and teach courses on it. We also install many different lighting systems, including LED. You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Jerry says, Then why can't you use standard incandescent dimmers with LED bulbs? Which is wrong because you can use "standard" dimmers, but the LED bulb has to be designed for it. Which they aren't for many reasons that I won't get into here. Try reading a little... http://www.ledsmagazine.com/articles...-magazine.html This article is sorely lacking in facts. Notice the title: "LED lighting must work with legacy dimming technologies". There are a number of problems with dimmable LED bulbs and the standard triac dimmer. See above. And I suggest you read more reliable information. LED bulb manufacturer's information is a better start. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/28/2014 7:23 PM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? Yes, for LED bulbs. Once again you show your ignorance. However, the simplest way to see that the light output is controlled by the applied voltage is to simply look at the base of a dimmable bulb and note that there are only two connections; no third connection for a control, just the same as all other light bulbs. Which means nothing. Some are dimmable and some are not because it takes more parts to make a dimmable bulb and the demand for them is less than that for non-dimmable bulbs. To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. Nope; light bulbs run at a rated voltage which is the standard voltage for the country in which they are sold; US light bulbs are rated for 120v, UK bulbs for whatever the voltage is over there, I think 240V. You are just arguing for the sake of arguing. No, I am arguing from facts - unlike you. I've been in the business of installing lighting control (and other things) for 11 years now. We install numerous LED control systems every year. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? You can if the bulb is specified as dimmable; some are, and some are not and they all use the standard two connection E26 base. Wrong again. A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. None of this has anything to do with high voltage. It has to do with the current required by the bulbs. The standard US wall outlet is rated at 15 Amps. A Phillips A21 75W replacement LED bulb draws 15W at 120V (0.125A) and is dimmable. Yes, and at 3V that would require 5 amps. At 120V that would be 600W, not 15W. http://www.usa.philips.com/c-p/04667...white-dimmable You obviously are unfamiliar with the structure of LED bulbs. You obiously have never noticed that the base of an LED bulb is identical to that of an incandescent, i.e. two wire E26 base, and that standard wall outlets in the US are 15 Amps. Which only means they can plug into a standard socket and run off of 120V. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
In rec.radio.amateur.boatanchors Jerry Stuckle wrote:
On 11/28/2014 7:23 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? Yes, for LED bulbs. Once again you show your ignorance. Once again you are arguing for the sake of arguing. However, the simplest way to see that the light output is controlled by the applied voltage is to simply look at the base of a dimmable bulb and note that there are only two connections; no third connection for a control, just the same as all other light bulbs. Which means nothing. Which means there can not be a control wire for a variable regulator. The only input a light bulb has is the input voltage. Some are dimmable and some are not because it takes more parts to make a dimmable bulb and the demand for them is less than that for non-dimmable bulbs. To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. Nope; light bulbs run at a rated voltage which is the standard voltage for the country in which they are sold; US light bulbs are rated for 120v, UK bulbs for whatever the voltage is over there, I think 240V. You are just arguing for the sake of arguing. No, I am arguing from facts - unlike you. I've been in the business of installing lighting control (and other things) for 11 years now. We install numerous LED control systems every year. I forgot that you are an expert on EVERYTHING and to call into question anything you say is the ultimate insult. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? You can if the bulb is specified as dimmable; some are, and some are not and they all use the standard two connection E26 base. Wrong again. Yes, right again. Light bulbs in the US use the E26 base and some are dimmable and some are not. If you have doubts, go into Home Depot, Lowe's, or any place that sells light bulbs and look. A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. None of this has anything to do with high voltage. It has to do with the current required by the bulbs. Which is two orders of magnitudes less than what a standard US outlet is capable of supplying. The standard US wall outlet is rated at 15 Amps. A Phillips A21 75W replacement LED bulb draws 15W at 120V (0.125A) and is dimmable. Yes, and at 3V that would require 5 amps. At 120V that would be 600W, not 15W. So what is your claim here; that LED light bulbs HAVE to hae a transformer? http://www.usa.philips.com/c-p/04667...white-dimmable You obviously are unfamiliar with the structure of LED bulbs. You obiously have never noticed that the base of an LED bulb is identical to that of an incandescent, i.e. two wire E26 base, and that standard wall outlets in the US are 15 Amps. Which only means they can plug into a standard socket and run off of 120V. Again you are arguing for the sake of arguing. How long until you start with your usual ad hominems? -- Jim Pennino |
High brightness LEDs?
On 11/28/2014 9:10 PM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 7:23 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? Yes, for LED bulbs. Once again you show your ignorance. Once again you are arguing for the sake of arguing. No, I'm just telling you that you are wrong - and why. YOU are the one arguing for the sake of arguing - and in the process, proving your ignorance. However, the simplest way to see that the light output is controlled by the applied voltage is to simply look at the base of a dimmable bulb and note that there are only two connections; no third connection for a control, just the same as all other light bulbs. Which means nothing. Which means there can not be a control wire for a variable regulator. The only input a light bulb has is the input voltage. So what? You don't need a control wire for a dimmable LED bulb (or any other). It's in the signal being fed to the bulb. Some are dimmable and some are not because it takes more parts to make a dimmable bulb and the demand for them is less than that for non-dimmable bulbs. To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. Nope; light bulbs run at a rated voltage which is the standard voltage for the country in which they are sold; US light bulbs are rated for 120v, UK bulbs for whatever the voltage is over there, I think 240V. You are just arguing for the sake of arguing. No, I am arguing from facts - unlike you. I've been in the business of installing lighting control (and other things) for 11 years now. We install numerous LED control systems every year. I forgot that you are an expert on EVERYTHING and to call into question anything you say is the ultimate insult. You've just proven once again that you're an expert in NOTHING. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? You can if the bulb is specified as dimmable; some are, and some are not and they all use the standard two connection E26 base. Wrong again. Yes, right again. Light bulbs in the US use the E26 base and some are dimmable and some are not. If you have doubts, go into Home Depot, Lowe's, or any place that sells light bulbs and look. I never said anything different. What I said was that LED bulbs cannot be dimmed with a standard incandescent dimmer. A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. None of this has anything to do with high voltage. It has to do with the current required by the bulbs. Which is two orders of magnitudes less than what a standard US outlet is capable of supplying. Sure. But you miss the fact that 5 amps is 5 amps - whether at 3V or 120V. The standard US wall outlet is rated at 15 Amps. A Phillips A21 75W replacement LED bulb draws 15W at 120V (0.125A) and is dimmable. Yes, and at 3V that would require 5 amps. At 120V that would be 600W, not 15W. So what is your claim here; that LED light bulbs HAVE to hae a transformer? Yes. The bulbs have electronic circuitry in the base which include a switching power supply and high frequency transformer. http://www.usa.philips.com/c-p/04667...white-dimmable You obviously are unfamiliar with the structure of LED bulbs. You obiously have never noticed that the base of an LED bulb is identical to that of an incandescent, i.e. two wire E26 base, and that standard wall outlets in the US are 15 Amps. Which only means they can plug into a standard socket and run off of 120V. Again you are arguing for the sake of arguing. How long until you start with your usual ad hominems? Which just shows that you are arguing for the sake of arguing, and in doing so, showing your ignorance. As for the ad hominem attacks - you're the king of those, as has been repeatedly proven. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/28/2014 7:05 PM, rickman wrote:
On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Jerry says, Then why can't you use standard incandescent dimmers with LED bulbs? Which is wrong because you can use "standard" dimmers, but the LED bulb has to be designed for it. Try reading a little... http://www.ledsmagazine.com/articles...-magazine.html Rickman, here's a better page from the manufacturer of dimmers (and one of the lines we carry): http://www.lutron.com/en-US/Educatio...LsandLEDs.aspx Note the paragraph under "Do all LED and CFL light bulbs work with all dimmers?" -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/28/2014 8:31 PM, wrote:
In rec.radio.amateur.boatanchors rickman wrote: On 11/28/2014 7:37 PM, wrote: snip See: http://en.wikipedia.org/wiki/Thyristor#Applications Please be as pedantic as you like. You are wrong. No, I am not, and I am being precise in my language. The very article you reference shows that the dimmer works by controlling the phase angle over which the AC voltage is passed to the load. Which is the phase angle, or more properly, the conduction angle of the contolling device, not the phase angle of the AC source. If the voltage is turned off for part of the conduction cycle, the average voltage changes. This is Electronics 101. There are *many* LED bulbs which can be dimmed by this standard type of dimmer. Yes, there are, but that is irrelevant to how a dimmer works and only relevant to how the bulb works. As the reference I provide shows, What reference? these bulbs include smarts to measure this phase angle You mean conduction angle? You can't measure a phase angle absent a reference signal of a known phase. Again, Electronic 101. and adjust the bulb brightness accordingly. I have several in my home. Whoopee!! Ok, if you really want to discuss this let me know. -- Rick |
High brightness LEDs?
On 11/28/2014 8:52 PM, Jerry Stuckle wrote:
On 11/28/2014 7:05 PM, rickman wrote: On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, Sorry, but lighting control has been my job for much of the last 11 years. I am considered an expert in it by many of my peers and teach courses on it. We also install many different lighting systems, including LED. You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Jerry says, Then why can't you use standard incandescent dimmers with LED bulbs? Which is wrong because you can use "standard" dimmers, but the LED bulb has to be designed for it. Which they aren't for many reasons that I won't get into here. Really? So the standard dimmers in my home can't work with the dimmable LED bulbs they are connected to and seem to control just fine? Try reading a little... http://www.ledsmagazine.com/articles...-magazine.html This article is sorely lacking in facts. Notice the title: "LED lighting must work with legacy dimming technologies". There are a number of problems with dimmable LED bulbs and the standard triac dimmer. See above. And I suggest you read more reliable information. LED bulb manufacturer's information is a better start. How do you explain the several LED bulbs I have working on standard dimmers in my home? -- Rick |
High brightness LEDs?
On 11/28/2014 9:34 PM, Jerry Stuckle wrote:
On 11/28/2014 7:05 PM, rickman wrote: On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Jerry says, Then why can't you use standard incandescent dimmers with LED bulbs? Which is wrong because you can use "standard" dimmers, but the LED bulb has to be designed for it. Try reading a little... http://www.ledsmagazine.com/articles...-magazine.html Rickman, here's a better page from the manufacturer of dimmers (and one of the lines we carry): http://www.lutron.com/en-US/Educatio...LsandLEDs.aspx Note the paragraph under "Do all LED and CFL light bulbs work with all dimmers?" That has even less information than the page I referred you to. Your link says nothing about LED lights in general, only the Lutron devices. As the article I referenced indicated, LEDs can be made to work with generic phase control dimmers and the several LED bulbs I have that work prove the point. I especially like Lutron's compatibility list. They have a wide definition of "compatible".... "Products on this list are considered compatible with the respective Lutron C·L dimmers. Depending on the quality of the bulb you select, compatible bulbs may still: - have less dimming range than an incandescent or halogen bulb - dim less smoothly than an incandescent or halogen bulb - flicker or shimmer at certain light levels - buzz" LOL. If the combination does any of these things I don't consider that to be "compatible". Actually I find Lutron to have some real crap product as well as very poor customer support. In order to assure I could get compatible dimmer and lamp, I bought an LED fixture that listed part numbers for compatible dimmers (tested in conjunction with the dimmer companies) and bought a compatible Lutron dimmer. The result was they didn't work properly. Clearly this particular fixture was *not* compatible with generic dimmers and wasn't even compatible with the specified dimmer. I contacted both Lutron and the company who made the fixture. I don't recall the response of the LED fixture company but Lutron simply recommended another dimmer with no mention of why they were on the compatibility list and yet were not compatible. -- Rick |
High brightness LEDs?
On 11/28/2014 10:39 PM, rickman wrote:
On 11/28/2014 8:52 PM, Jerry Stuckle wrote: On 11/28/2014 7:05 PM, rickman wrote: On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, Sorry, but lighting control has been my job for much of the last 11 years. I am considered an expert in it by many of my peers and teach courses on it. We also install many different lighting systems, including LED. You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Jerry says, Then why can't you use standard incandescent dimmers with LED bulbs? Which is wrong because you can use "standard" dimmers, but the LED bulb has to be designed for it. Which they aren't for many reasons that I won't get into here. Really? So the standard dimmers in my home can't work with the dimmable LED bulbs they are connected to and seem to control just fine? Try reading a little... http://www.ledsmagazine.com/articles...-magazine.html This article is sorely lacking in facts. Notice the title: "LED lighting must work with legacy dimming technologies". There are a number of problems with dimmable LED bulbs and the standard triac dimmer. See above. And I suggest you read more reliable information. LED bulb manufacturer's information is a better start. How do you explain the several LED bulbs I have working on standard dimmers in my home? Rick, How do you explain the manufacturer of dimmers says standard dimmers cannot be used reliably? But since you want the details, here is a start. There are a number of problems with standard incandescent dimmers. Since they cut off the initial phase of the positive and negative phases, when they start conducting there is a large surge of power. This surge causes additional heat buildup in a switching power supply and can cause premature failure of the bulb and/or dimmer. If you look at travel adapters for running U.S. devices on European voltages, you'll find two different types - electronic switching and standard transformer. You will notice the electronic switching supplies are higher powered have cautions not to use them with electronic loads such as radios and TV's. This is for the same reason as dimmers on LEDs - the dimmer does not put out a clean waveform. Transformer-based travel adapters have no such limitation because they put out a clean signal, but have lower power ratings. There are other problems, also. Conventional dimmers having a minimum load (minimum current flowing through triacs). If the minimum load to maintain conduction is 10W, a 15W LED will only dim to 2/3 power before turning off. Dimmable LED bulbs are also very sensitive to voltage fluctuations, and can flicker with variations in the line voltage. This is especially true when operating near that cutoff voltage noted above. Also, since LED's respond immediately to current changes (unlike incandescent, which have a high thermal inertia), there is a tendency for them to flicker when the wrong dimmer is used. Sure, it's 120 hz flicker - but some people are sensitive to it and can suffer headaches. Worst case, but fortunately very rare, the flash can cause epileptic seizures those sensitive to it. These are some of the most serious problems with using conventional dimmers with LED bulbs. It's also why manufacturers spend a lot of money developing special dimmers for LED bulbs. I would also recommend you check other manufacturer's of LED bulb dimmers. You will find they all have the same cautions. But since these pages are intended for consumers, they obviously leave out the technical details. Those are available to dealers, though, either through dealer-only pages or dealer support. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
In rec.radio.amateur.boatanchors Jerry Stuckle wrote:
snip Note the paragraph under "Do all LED and CFL light bulbs work with all dimmers?" No, thet don't, it depends on the manufacturer of the bulb. Here's a couple of references from someone that does not sell light bulbs or dimmers: http://www.cnet.com/how-to/five-thin...ing-led-bulbs/ http://www.cnet.com/news/which-led-l...t-for-dimming/ -- Jim Pennino |
High brightness LEDs?
In rec.radio.amateur.boatanchors Jerry Stuckle wrote:
On 11/28/2014 9:10 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: snip No, I am arguing from facts - unlike you. I've been in the business of installing lighting control (and other things) for 11 years now. We install numerous LED control systems every year. I forgot that you are an expert on EVERYTHING and to call into question anything you say is the ultimate insult. You've just proven once again that you're an expert in NOTHING. And you've just proven once again that all that you know is what you have supposedly done, not what exists in the world. Here is a couple of articles on the subject from people who do NOT make a living selling either light bulbs or controls. http://www.cnet.com/how-to/five-thin...ing-led-bulbs/ http://www.cnet.com/news/which-led-l...t-for-dimming/ It seems that yes, dimmable LED bulbs are available for legacy dimmers, and they work just fine. snip -- Jim Pennino |
High brightness LEDs?
Jerry Stuckle wrote:
No, these have electronic power supplies in them. Otherwise they would dissipate huge amounts of heat. Think about it. LED's run at about 3V. That means a 9W LED requires about 3 amps of power. 3 amps at 240V is 720W - or about 711W of power wasted. They would be way less efficient than any other type of bulbs. Plus LED's run on DC and would not work as efficiently on 50Hz AC. 9W is an enormous amount of power for an LED. The LEDs used to replace pilot lamps are normally running 10mA, not 3 amps. This is what allows a dropping resistor to be used. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
High brightness LEDs?
On 11/28/2014 11:01 PM, Jerry Stuckle wrote:
On 11/28/2014 10:39 PM, rickman wrote: On 11/28/2014 8:52 PM, Jerry Stuckle wrote: On 11/28/2014 7:05 PM, rickman wrote: On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, Sorry, but lighting control has been my job for much of the last 11 years. I am considered an expert in it by many of my peers and teach courses on it. We also install many different lighting systems, including LED. You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Jerry says, Then why can't you use standard incandescent dimmers with LED bulbs? Which is wrong because you can use "standard" dimmers, but the LED bulb has to be designed for it. Which they aren't for many reasons that I won't get into here. Really? So the standard dimmers in my home can't work with the dimmable LED bulbs they are connected to and seem to control just fine? Try reading a little... http://www.ledsmagazine.com/articles...-magazine.html This article is sorely lacking in facts. Notice the title: "LED lighting must work with legacy dimming technologies". There are a number of problems with dimmable LED bulbs and the standard triac dimmer. See above. And I suggest you read more reliable information. LED bulb manufacturer's information is a better start. How do you explain the several LED bulbs I have working on standard dimmers in my home? Rick, How do you explain the manufacturer of dimmers says standard dimmers cannot be used reliably? I don't see where they said that. They are only talking about their own products. But since you want the details, here is a start. There are a number of problems with standard incandescent dimmers. Since they cut off the initial phase of the positive and negative phases, when they start conducting there is a large surge of power. This surge causes additional heat buildup in a switching power supply and can cause premature failure of the bulb and/or dimmer. Dealing with this heat would be part of the design requirements for a "dimmable" LED bulb, no? If you look at travel adapters for running U.S. devices on European voltages, you'll find two different types - electronic switching and standard transformer. You will notice the electronic switching supplies are higher powered have cautions not to use them with electronic loads such as radios and TV's. This is for the same reason as dimmers on LEDs - the dimmer does not put out a clean waveform. Transformer-based travel adapters have no such limitation because they put out a clean signal, but have lower power ratings. There are other problems, also. Conventional dimmers having a minimum load (minimum current flowing through triacs). If the minimum load to maintain conduction is 10W, a 15W LED will only dim to 2/3 power before turning off. Dimmable LED bulbs are also very sensitive to voltage fluctuations, and can flicker with variations in the line voltage. This is especially true when operating near that cutoff voltage noted above. Again, this is a design issue and one that is present even when not being dimmed. Also, since LED's respond immediately to current changes (unlike incandescent, which have a high thermal inertia), there is a tendency for them to flicker when the wrong dimmer is used. Sure, it's 120 hz flicker - but some people are sensitive to it and can suffer headaches. Worst case, but fortunately very rare, the flash can cause epileptic seizures those sensitive to it. I have seen no information that 120 Hz flicker is in any way noticeable or that anyone is sensitive to it. Monitors have flickered at much lower rates for a very long time. Plus... again, this is an issue without dimmers. These are some of the most serious problems with using conventional dimmers with LED bulbs. It's also why manufacturers spend a lot of money developing special dimmers for LED bulbs. I would also recommend you check other manufacturer's of LED bulb dimmers. You will find they all have the same cautions. But since these pages are intended for consumers, they obviously leave out the technical details. Those are available to dealers, though, either through dealer-only pages or dealer support. And yet, I have dimmers that work... -- Rick |
High brightness LEDs?
On Friday, November 28, 2014 8:20:14 AM UTC-5, gareth wrote:
These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? There is not a whole lot in there. AC/DC supply, Buck/Boost controller chip with triac dimmer sensing (if it's a dimmable LED lamp), small inductors caps, rectifiers. TI and ONSemi have controllers and reference designs at their web sites. I don't know if the govt regulators are requiring any sort of power factor correction. There is a whole lot of power factor correction circuitry going into higher current consumer goods in the EU so there should be good parts(inductors rectifiers, switches, caps) in a few years when consumers begin yearning for newer models. |
High brightness LEDs?
On 11/28/2014 11:11 PM, Scott Dorsey wrote:
Jerry Stuckle wrote: No, these have electronic power supplies in them. Otherwise they would dissipate huge amounts of heat. Think about it. LED's run at about 3V. That means a 9W LED requires about 3 amps of power. 3 amps at 240V is 720W - or about 711W of power wasted. They would be way less efficient than any other type of bulbs. Plus LED's run on DC and would not work as efficiently on 50Hz AC. 9W is an enormous amount of power for an LED. The LEDs used to replace pilot lamps are normally running 10mA, not 3 amps. This is what allows a dropping resistor to be used. --scott You are confusing LEDs with LED bulbs. A 9W LED bulb is equivalent to about a 60W incandescent bulb. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/28/2014 11:16 PM, rickman wrote:
On 11/28/2014 11:01 PM, Jerry Stuckle wrote: On 11/28/2014 10:39 PM, rickman wrote: On 11/28/2014 8:52 PM, Jerry Stuckle wrote: On 11/28/2014 7:05 PM, rickman wrote: On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, Sorry, but lighting control has been my job for much of the last 11 years. I am considered an expert in it by many of my peers and teach courses on it. We also install many different lighting systems, including LED. You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Jerry says, Then why can't you use standard incandescent dimmers with LED bulbs? Which is wrong because you can use "standard" dimmers, but the LED bulb has to be designed for it. Which they aren't for many reasons that I won't get into here. Really? So the standard dimmers in my home can't work with the dimmable LED bulbs they are connected to and seem to control just fine? Try reading a little... http://www.ledsmagazine.com/articles...-magazine.html This article is sorely lacking in facts. Notice the title: "LED lighting must work with legacy dimming technologies". There are a number of problems with dimmable LED bulbs and the standard triac dimmer. See above. And I suggest you read more reliable information. LED bulb manufacturer's information is a better start. How do you explain the several LED bulbs I have working on standard dimmers in my home? Rick, How do you explain the manufacturer of dimmers says standard dimmers cannot be used reliably? I don't see where they said that. They are only talking about their own products. "No, unlike incandescent bulbs that work with almost any dimmer, LED and CFL bulbs perform differently depending on the dimmer you install. You will need to select a dimmer designed specifically for dimmable LED/CFL bulbs." That seems to indicate they won't work reliably. But since you want the details, here is a start. There are a number of problems with standard incandescent dimmers. Since they cut off the initial phase of the positive and negative phases, when they start conducting there is a large surge of power. This surge causes additional heat buildup in a switching power supply and can cause premature failure of the bulb and/or dimmer. Dealing with this heat would be part of the design requirements for a "dimmable" LED bulb, no? Not when used with a non-LED bulb dimmer. Simple LED dimmers use MOSFETs to trim the trailing part of the waveform, eliminating the surge. You can argue design all you want. But the fact is this surge current creates heat - which wastes energy, making the bulb less efficient. And adding what is necessary to handle the extra current would add cost, raising the price. Both make the product less competitive. If you look at travel adapters for running U.S. devices on European voltages, you'll find two different types - electronic switching and standard transformer. You will notice the electronic switching supplies are higher powered have cautions not to use them with electronic loads such as radios and TV's. This is for the same reason as dimmers on LEDs - the dimmer does not put out a clean waveform. Transformer-based travel adapters have no such limitation because they put out a clean signal, but have lower power ratings. There are other problems, also. Conventional dimmers having a minimum load (minimum current flowing through triacs). If the minimum load to maintain conduction is 10W, a 15W LED will only dim to 2/3 power before turning off. Dimmable LED bulbs are also very sensitive to voltage fluctuations, and can flicker with variations in the line voltage. This is especially true when operating near that cutoff voltage noted above. Again, this is a design issue and one that is present even when not being dimmed. No, they do not flicker at full power. They may dim a bit, but they will not flicker. LED dimmers provide a stable voltage to the bulb, eliminating flicker. Also, since LED's respond immediately to current changes (unlike incandescent, which have a high thermal inertia), there is a tendency for them to flicker when the wrong dimmer is used. Sure, it's 120 hz flicker - but some people are sensitive to it and can suffer headaches. Worst case, but fortunately very rare, the flash can cause epileptic seizures those sensitive to it. I have seen no information that 120 Hz flicker is in any way noticeable or that anyone is sensitive to it. Monitors have flickered at much lower rates for a very long time. Plus... again, this is an issue without dimmers. You haven't been reading the medical engineering data. It is not so much an issue without dimmers because there is a slight inertial effect in the switching supply (capacitors) such that the bulb doesn't dim to 0, even at zero crossing. However, when you start cutting the AC cycle going to the bulb, the capacitors totally discharge and you get a relatively long period when the LEDs are completely black. Monitors are not a problem because they work completely differently. First of all, the original CRTs had a phosphor, which had a certain amount of persistence. Newer LCD monitors (even "LED" monitors are LCD monitors, just with an LED backlight) do not turn pixels on and off at a scan rate. These are some of the most serious problems with using conventional dimmers with LED bulbs. It's also why manufacturers spend a lot of money developing special dimmers for LED bulbs. I would also recommend you check other manufacturer's of LED bulb dimmers. You will find they all have the same cautions. But since these pages are intended for consumers, they obviously leave out the technical details. Those are available to dealers, though, either through dealer-only pages or dealer support. And yet, I have dimmers that work... See above - and check other manufactures of LED dimmers, also. They all say the same thing. Argue with them, not me. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/28/2014 10:51 PM, rickman wrote:
On 11/28/2014 9:34 PM, Jerry Stuckle wrote: On 11/28/2014 7:05 PM, rickman wrote: On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Jerry says, Then why can't you use standard incandescent dimmers with LED bulbs? Which is wrong because you can use "standard" dimmers, but the LED bulb has to be designed for it. Try reading a little... http://www.ledsmagazine.com/articles...-magazine.html Rickman, here's a better page from the manufacturer of dimmers (and one of the lines we carry): http://www.lutron.com/en-US/Educatio...LsandLEDs.aspx Note the paragraph under "Do all LED and CFL light bulbs work with all dimmers?" That has even less information than the page I referred you to. But it is accurate information from a manufacturer. Your link says nothing about LED lights in general, only the Lutron devices. As the article I referenced indicated, LEDs can be made to work with generic phase control dimmers and the several LED bulbs I have that work prove the point. I especially like Lutron's compatibility list. They have a wide definition of "compatible".... Of course. But check any manufacturer of LED dimmers. They all say the same thing in one way or another. "Products on this list are considered compatible with the respective Lutron C·L dimmers. Depending on the quality of the bulb you select, compatible bulbs may still: - have less dimming range than an incandescent or halogen bulb - dim less smoothly than an incandescent or halogen bulb - flicker or shimmer at certain light levels - buzz" LOL. If the combination does any of these things I don't consider that to be "compatible". No dimmer manufacturer can control how bulbs are built. Lutron does its best to specify what will and will not work. Actually I find Lutron to have some real crap product as well as very poor customer support. In order to assure I could get compatible dimmer and lamp, I bought an LED fixture that listed part numbers for compatible dimmers (tested in conjunction with the dimmer companies) and bought a compatible Lutron dimmer. The result was they didn't work properly. Clearly this particular fixture was *not* compatible with generic dimmers and wasn't even compatible with the specified dimmer. They have excellent dealer support. And most of their sales is through dealers like us. I contacted both Lutron and the company who made the fixture. I don't recall the response of the LED fixture company but Lutron simply recommended another dimmer with no mention of why they were on the compatibility list and yet were not compatible. Probably because they are not high on consumer sales. Dealers like us get excellent support from them (and most manufacturers). I can even call and talk directly with an engineer. Their main consumer support is through the dealer you purchased it from. If you got it from the internet or similar, you got what you paid for. If you got it from an authorized Lutron dealer, they should support you. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/28/2014 11:02 PM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle wrote: snip Note the paragraph under "Do all LED and CFL light bulbs work with all dimmers?" No, thet don't, it depends on the manufacturer of the bulb. Here's a couple of references from someone that does not sell light bulbs or dimmers: http://www.cnet.com/how-to/five-thin...ing-led-bulbs/ http://www.cnet.com/news/which-led-l...t-for-dimming/ I find cnet to be more reliable than PC Magazine - but that isn't saying much. They are a consumer-oriented site, and dumb down their reports significantly to meet the average reader's intelligence (which means about the third-grade level - seriously). And please note the first reference is a person who is a "CNET How-to expert" and the second a "text-based adventure connoisseur".. Neither is an engineer. What are their credentials - except that they got paid? I'll go by the manufacturers which product the goods - and they all say the same thing. When in doubt, find out from the experts. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/28/2014 11:09 PM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 9:10 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: snip No, I am arguing from facts - unlike you. I've been in the business of installing lighting control (and other things) for 11 years now. We install numerous LED control systems every year. I forgot that you are an expert on EVERYTHING and to call into question anything you say is the ultimate insult. You've just proven once again that you're an expert in NOTHING. And you've just proven once again that all that you know is what you have supposedly done, not what exists in the world. Here is a couple of articles on the subject from people who do NOT make a living selling either light bulbs or controls. http://www.cnet.com/how-to/five-thin...ing-led-bulbs/ http://www.cnet.com/news/which-led-l...t-for-dimming/ It seems that yes, dimmable LED bulbs are available for legacy dimmers, and they work just fine. snip Right. By a "CNET How-to expert" and a "text-based adventure game connoisseur". Real experts! I'll go by what the engineers who design the devices say. You keep reading the funnies. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/28/2014 11:46 PM, Jerry Stuckle wrote:
On 11/28/2014 11:16 PM, rickman wrote: On 11/28/2014 11:01 PM, Jerry Stuckle wrote: On 11/28/2014 10:39 PM, rickman wrote: On 11/28/2014 8:52 PM, Jerry Stuckle wrote: On 11/28/2014 7:05 PM, rickman wrote: On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, Sorry, but lighting control has been my job for much of the last 11 years. I am considered an expert in it by many of my peers and teach courses on it. We also install many different lighting systems, including LED. You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Jerry says, Then why can't you use standard incandescent dimmers with LED bulbs? Which is wrong because you can use "standard" dimmers, but the LED bulb has to be designed for it. Which they aren't for many reasons that I won't get into here. Really? So the standard dimmers in my home can't work with the dimmable LED bulbs they are connected to and seem to control just fine? Try reading a little... http://www.ledsmagazine.com/articles...-magazine.html This article is sorely lacking in facts. Notice the title: "LED lighting must work with legacy dimming technologies". There are a number of problems with dimmable LED bulbs and the standard triac dimmer. See above. And I suggest you read more reliable information. LED bulb manufacturer's information is a better start. How do you explain the several LED bulbs I have working on standard dimmers in my home? Rick, How do you explain the manufacturer of dimmers says standard dimmers cannot be used reliably? I don't see where they said that. They are only talking about their own products. "No, unlike incandescent bulbs that work with almost any dimmer, LED and CFL bulbs perform differently depending on the dimmer you install. You will need to select a dimmer designed specifically for dimmable LED/CFL bulbs." That seems to indicate they won't work reliably. And yet I have units in my home that work...reliably. Rather than cite dimmer companies, why not cite the bulb companies? That is what we are discussing. But since you want the details, here is a start. There are a number of problems with standard incandescent dimmers. Since they cut off the initial phase of the positive and negative phases, when they start conducting there is a large surge of power. This surge causes additional heat buildup in a switching power supply and can cause premature failure of the bulb and/or dimmer. Dealing with this heat would be part of the design requirements for a "dimmable" LED bulb, no? Not when used with a non-LED bulb dimmer. Simple LED dimmers use MOSFETs to trim the trailing part of the waveform, eliminating the surge. You can argue design all you want. But the fact is this surge current creates heat - which wastes energy, making the bulb less efficient. And adding what is necessary to handle the extra current would add cost, raising the price. Both make the product less competitive. I never said anything about "wasted" energy or competitiveness. I said LED bulbs can are are designed that work with existing dimmers. If you look at travel adapters for running U.S. devices on European voltages, you'll find two different types - electronic switching and standard transformer. You will notice the electronic switching supplies are higher powered have cautions not to use them with electronic loads such as radios and TV's. This is for the same reason as dimmers on LEDs - the dimmer does not put out a clean waveform. Transformer-based travel adapters have no such limitation because they put out a clean signal, but have lower power ratings. There are other problems, also. Conventional dimmers having a minimum load (minimum current flowing through triacs). If the minimum load to maintain conduction is 10W, a 15W LED will only dim to 2/3 power before turning off. Dimmable LED bulbs are also very sensitive to voltage fluctuations, and can flicker with variations in the line voltage. This is especially true when operating near that cutoff voltage noted above. Again, this is a design issue and one that is present even when not being dimmed. No, they do not flicker at full power. They may dim a bit, but they will not flicker. LED dimmers provide a stable voltage to the bulb, eliminating flicker. There is nothing inherent in a phase angle dimmer that causes flickering in a properly designed bulb. A few uF capacitance takes care of that. Also, since LED's respond immediately to current changes (unlike incandescent, which have a high thermal inertia), there is a tendency for them to flicker when the wrong dimmer is used. Sure, it's 120 hz flicker - but some people are sensitive to it and can suffer headaches. Worst case, but fortunately very rare, the flash can cause epileptic seizures those sensitive to it. I have seen no information that 120 Hz flicker is in any way noticeable or that anyone is sensitive to it. Monitors have flickered at much lower rates for a very long time. Plus... again, this is an issue without dimmers. You haven't been reading the medical engineering data. It is not so much an issue without dimmers because there is a slight inertial effect in the switching supply (capacitors) such that the bulb doesn't dim to 0, even at zero crossing. However, when you start cutting the AC cycle going to the bulb, the capacitors totally discharge and you get a relatively long period when the LEDs are completely black. Unless you add a bit more capacitance... again a bulb design issue. Monitors are not a problem because they work completely differently. First of all, the original CRTs had a phosphor, which had a certain amount of persistence. Newer LCD monitors (even "LED" monitors are LCD monitors, just with an LED backlight) do not turn pixels on and off at a scan rate. Lol. Monitors do flicker and have always flickered. At 60 Hz most monitors bother me a lot. At 80 Hz not at all. I don't know anyone or have read anything that says 120 Hz is not sufficient to preclude the perception of flicker. These are some of the most serious problems with using conventional dimmers with LED bulbs. It's also why manufacturers spend a lot of money developing special dimmers for LED bulbs. I would also recommend you check other manufacturer's of LED bulb dimmers. You will find they all have the same cautions. But since these pages are intended for consumers, they obviously leave out the technical details. Those are available to dealers, though, either through dealer-only pages or dealer support. And yet, I have dimmers that work... See above - and check other manufactures of LED dimmers, also. They all say the same thing. Argue with them, not me. Ok, I guess we are done then. -- Rick |
High brightness LEDs?
On 11/28/2014 11:50 PM, Jerry Stuckle wrote:
On 11/28/2014 10:51 PM, rickman wrote: On 11/28/2014 9:34 PM, Jerry Stuckle wrote: On 11/28/2014 7:05 PM, rickman wrote: On 11/28/2014 6:16 PM, Jerry Stuckle wrote: On 11/28/2014 5:24 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? To specifically answer your question, you design a regulator who's output is some precentage of the raw input as opposed to a regulator who's output is always equal to some reference voltage. Again, it all depends. And to be yet more specific, since LED brightness is proportional to current and resistors would waste power, the regulator would be a current regulator with an average current output proportional to the raw input voltage. Then why can't you use standard incandescent dimmers with LED bulbs? A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. True for IC regulators. Hoever high voltage transistors exist these days which makes designing a high voltage regulator pretty trivial. Sure. But how do you handle the current requirements without some kind of transformer? Well, assuming you want some voltage greater than the wall plug maximum, the need for a transformer is pretty much a given unless some sort of voltage multiplying rectifier is sufficient for the need, which is where the current requirement becomes relevant. However, the subject was high voltage regulators, not where does the raw high voltage come from. And where do you get the current necessary to supply the LEDs in the bulbs? A typical LED required around 3V (usually 2.7V to 3.3V, depending on the LED)? A 9 watt LED would require 3 amps of current. Or, if the LEDs were in series, something less. But without a transformer, the current would still exceed that of an incandescent bulb. You obviously are unfamiliar with the structure of LED bulbs. You two are both speculating and have limited information to base either of your opinions on. Jim says, You do realize that a dimmable light bulb is dimmed by changeing the supply voltage and not by anything else connected to the bulb? which is not correct in that most dimmers work by reducing the phase angle of the applied AC or to reduce noise some simply don't turn on for entire half cycles. Jerry says, Then why can't you use standard incandescent dimmers with LED bulbs? Which is wrong because you can use "standard" dimmers, but the LED bulb has to be designed for it. Try reading a little... http://www.ledsmagazine.com/articles...-magazine.html Rickman, here's a better page from the manufacturer of dimmers (and one of the lines we carry): http://www.lutron.com/en-US/Educatio...LsandLEDs.aspx Note the paragraph under "Do all LED and CFL light bulbs work with all dimmers?" That has even less information than the page I referred you to. But it is accurate information from a manufacturer. Your link says nothing about LED lights in general, only the Lutron devices. As the article I referenced indicated, LEDs can be made to work with generic phase control dimmers and the several LED bulbs I have that work prove the point. I especially like Lutron's compatibility list. They have a wide definition of "compatible".... Of course. But check any manufacturer of LED dimmers. They all say the same thing in one way or another. "Products on this list are considered compatible with the respective Lutron C·L dimmers. Depending on the quality of the bulb you select, compatible bulbs may still: - have less dimming range than an incandescent or halogen bulb - dim less smoothly than an incandescent or halogen bulb - flicker or shimmer at certain light levels - buzz" LOL. If the combination does any of these things I don't consider that to be "compatible". No dimmer manufacturer can control how bulbs are built. Lutron does its best to specify what will and will not work. So why are you citing dimmer makers when we are discussing the bulbs? Actually I find Lutron to have some real crap product as well as very poor customer support. In order to assure I could get compatible dimmer and lamp, I bought an LED fixture that listed part numbers for compatible dimmers (tested in conjunction with the dimmer companies) and bought a compatible Lutron dimmer. The result was they didn't work properly. Clearly this particular fixture was *not* compatible with generic dimmers and wasn't even compatible with the specified dimmer. They have excellent dealer support. And most of their sales is through dealers like us. You mean dealers like Home Depot who have zero support other than letting you return the crap that doesn't work? Like I said, the box was labeled as being compatible with the "tested" dimmers. It wasn't unless you define "compatible" (by the Lutron web page) as - have less dimming range than an incandescent or halogen bulb - dim less smoothly than an incandescent or halogen bulb - flicker or shimmer at certain light levels - buzz" Obviously Lutron has a very broad definition of "compatible". I would stop using them as an authority if I were you. I contacted both Lutron and the company who made the fixture. I don't recall the response of the LED fixture company but Lutron simply recommended another dimmer with no mention of why they were on the compatibility list and yet were not compatible. Probably because they are not high on consumer sales. Dealers like us get excellent support from them (and most manufacturers). I can even call and talk directly with an engineer. Do me a favor and ask them why they consider flickering, less dimming range, unsmooth dimming and buzzing as being acceptable in compatible products. Their main consumer support is through the dealer you purchased it from. If you got it from the internet or similar, you got what you paid for. If you got it from an authorized Lutron dealer, they should support you. Sure, I expect I can *still* return it to Home Depot. But the point is Lutron and the lamp company has a crappy definition of "compatible" which means I won't be buying any more Lutron dimming products. By their own definition they work like crap. Meanwhile I have LED bulbs that do work properly with conventional dimmers. Also, you have not mentioned anything about how LED bulbs are design to work with *any* dimmers. The page I referenced provided a design that will provide a properly functioning LED bulb truly compatible with legacy dimmers. -- Rick |
High brightness LEDs?
On 11/28/2014 11:57 PM, Jerry Stuckle wrote:
On 11/28/2014 11:02 PM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: snip Note the paragraph under "Do all LED and CFL light bulbs work with all dimmers?" No, thet don't, it depends on the manufacturer of the bulb. Here's a couple of references from someone that does not sell light bulbs or dimmers: http://www.cnet.com/how-to/five-thin...ing-led-bulbs/ http://www.cnet.com/news/which-led-l...t-for-dimming/ I find cnet to be more reliable than PC Magazine - but that isn't saying much. They are a consumer-oriented site, and dumb down their reports significantly to meet the average reader's intelligence (which means about the third-grade level - seriously). And please note the first reference is a person who is a "CNET How-to expert" and the second a "text-based adventure connoisseur".. Neither is an engineer. What are their credentials - except that they got paid? I'll go by the manufacturers which product the goods - and they all say the same thing. When in doubt, find out from the experts. Great review link. I think this shows conclusively that there are LED bulbs that work with legacy dimmers. Regardless of what the "experts" may say. :) -- Rick |
High brightness LEDs?
On Fri, 28 Nov 2014, Jerry Stuckle wrote:
On 11/28/2014 4:11 PM, wrote: In rec.radio.amateur.boatanchors Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. Given that manufacturers want the least cost in a product, and the regulator in a light bulb would have no need for a variable regulator, and that these things are made in the millions, it would be extremely silly to assume that the regulator is anything other than a fixed regulator for LED's and is designed to handle the load of some fixed number of LED's. Once again, incorrect. Have you ever heard of "dimmable LED bulbs"? How do you dim without an adjustable regulator? That may be semantics. LEDs are current driven, voltage won't have much effect other than when fed through a resistor that does convert to current. More likely the LEDs would be driven with a square wave, and changing the ratio of on to off would vary the light output of the LED. Michael |
High brightness LEDs?
On Sat, 29 Nov 2014, Barry OGrady wrote:
On Fri, 28 Nov 2014 15:00:46 -0500, Michael Black wrote: On Fri, 28 Nov 2014, wrote: In rec.radio.amateur.boatanchors gareth wrote: These LED replacements for 240V mains lamps; if one were to open them, would one find a high voltage regulator suitable for some of our valve experiments and repairs? As the regulators are potted in and would be difficult to remove, and since LED's run on voltages on the order of 2-3 volts, no. How many 3 volt valves can you name? I think that point was that if a regulator was used to drop the line voltage to those 3volts, it could handle high voltage input. The probably false assumption is that the regulator would be variable from some very high output voltage to some very low output voltage, so one could use it for tubes by making that adjustment. A lot of IC regulators can't handle high voltage. If nothing else, nobody saw the need, it was the solid state age. So dissipation issues aside, most regulators expect at most a relatively low DC voltage input. Of course, one can run tubes on low voltage. The Collins 75S receiver line apparently kept plat voltage relatively low (somewhere around 120v if I remember right) which had certain advantages. One can run regular tubes at 12VDC on the plate, there were some articles in Popular Electronics about this, calling them "starved circuits". Or there were those tubes designed to run off 12VDC for those hybrid car radios, a last gasp before transistors took over completely. I had a hybrid car radio with four valves and two transistors. The RF amp, mixer, IF amp, and first audio used valves. Those valves had 12 volts on the plate. I assumed all the audio would be transitorized. But it was right at that point where transistors might not have yet been so good at higher frequencies, so tubes handled the radio part of the radio. Motorola had a hybrid "lunchbox" type transceiver. A diode mixer in the receiver, if I'm remembering right, the local oscillator chain was subminiature tubes, as well as the first IF, then a 455KHz transistorized IF strip and solid state audio. They had to keep the tubes because the transistors weren't good enough for VHF. I also had a valve test oscillator that ran off a 9 volt grid bias battery. Yes, that sort of thing would have been quite handy. Michael |
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