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High brightness LEDs?
On 11/29/2014 1:07 AM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle wrote: snip How do you explain the manufacturer of dimmers says standard dimmers cannot be used reliably? Because the manufacturer wants to sell their dimmers and their bulbs. Use Phillips bulbs and there is no problem http://www.cnet.com/news/which-led-l...t-for-dimming/ snip remainder Then why do all manufacturers say the same thing? And exactly what are the qualifications of the author? A "text-based adventure connoisseur"? I'll believe the engineers who design dimmers, not the funny pages. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/29/2014 9:15 AM, Jerry Stuckle wrote:
On 11/29/2014 1:07 AM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: snip How do you explain the manufacturer of dimmers says standard dimmers cannot be used reliably? Because the manufacturer wants to sell their dimmers and their bulbs. Use Phillips bulbs and there is no problem http://www.cnet.com/news/which-led-l...t-for-dimming/ snip remainder Then why do all manufacturers say the same thing? And exactly what are the qualifications of the author? A "text-based adventure connoisseur"? I'll believe the engineers who design dimmers, not the funny pages. You are being a bit silly about this. The guy did a *test* which was clearly pretty thorough, thorough enough that he could detect *and* record the flickering of the bulbs when dimmed. He pretty clearly doesn't have a manufacturer bias since the same company had the bulb that tested as the best and another which tested as the worst in the group. Unless the guy has a reputation for faking such tests, why would you doubt his work? Ignoring valid test data and preferring the opinion of manufacturers who have a clear stake in the game just seems odd. Do you deny that the tests show at least one brand and model LED bulb works perfectly well with a legacy dimmer? -- Rick |
High brightness LEDs?
On 11/29/2014 12:12 AM, rickman wrote:
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? Because of the claim that any dimmer can be used with LED bulbs. And depending on the bulbs, they may or may not work with dimmers - even ones specifically made for LED bulbs. For instance, there are a some cheap Chinese LED bulbs which claim to be dimmable - but don't work reliably with ANY dimmer. And when you use them with a dimmer, they don't last long. 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. Maybe the local store has no support, but that's not the end of their support. To become an authorized dealer, our tech people had to go through a lot of training (common for the better brands). Home Depot had to do the same thing, but obviously they don't have every employee in the country trained (nor could they maintain the training). And yes, "compatible" means they will work - but not necessarily how *well* they will work. And some bulbs work fine, while some don't - even when they are the same model from the same manufacturer. They have been a very reliable manufacturer for us in both the residential and commercial sectors for a number of years. When properly installed, we have had almost zero problems with their products. And we install a lot every year. But you don't like Lutron's comments? Here's another manufacturer: http://www.leviton.com/OA_HTML/Secti...minisite=10251 Or this one (a non-engineering sales pitch, but saying the same thing) http://www.legrand.us/resources-and-...l-dimmers.aspx (download the article) 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. Compatible does not mean it will work perfectly. True in ANY business. 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. No, their definition is the same as that in any market. Compatible does not mean things will work perfectly. As to the article - you mean the one titled "LED lighting must work with legacy dimming technologies"? The one with an obvious agenda? Did you even read the article? How about Table 1 where it states that phase dimmers have problems with LED lighting? In fact, some of the same problems I have already mentioned? And BTW - what are the author's credentials? Is he an engineer who knows what he's talking about, or just some blogger who's read a few articles? The lack of a short bio is noticeable. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/29/2014 1:13 AM, wrote:
In rec.radio.amateur.boatanchors rickman wrote: 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. :) Just the "experts" that have dimmers to sell... If they lied in their statements, the FTC would be after them in a second. They are very aggressive about such things. And not all manufacturers would be saying the same thing. But then you know everything, and you are always right. And anyone who disagrees with you is a liar or doesn't know what he's talking about. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/29/2014 1:15 AM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle wrote: 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. You mean the engineers working for the company that is trying to sell dimmers and bulbs? I'll go by the guy who doesn't have a dog in the race. If they lied in their statements, the FTC would be after them in a second. They are very aggressive about such things. And not all manufacturers would be saying the same thing. But then you know everything, and you are always right. And anyone who disagrees with you is a liar or doesn't know what he's talking about. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/29/2014 4:30 AM, Rob wrote:
Jerry Stuckle wrote: For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? "is it dimmable" refers to the use of a phase-cut TRIAC dimmer in combination with a retrofit LED bulb designed to run on mains power. No, some bulbs are not dimmable, period. Some are. None work reliably with triac dimmer controls. This combination does not work for all LED bulbs, because the electronics in the bulb are trying to put a constant current through the LED independent on the mains voltage, and now you are cutting down the mains power. (not even the voltage, really) True - but non-dimmable bulbs do not work with other dimmers for the same reason. You probably have a 13.8V stabilized DC supply in your shack. Can you use it as a variable-voltage supply by putting a dimmer in front of it? Completely unrelated. The LED electronics and the power supply work completely differently. No, not really. When you turn down the dimmer, the supply will first try all it can do to keep the voltage at 13.8, and at some point it can not achieve that anymore and the voltage will drop, but it will not be stabilized anymore. Similarly, a LED bulb may keep constant light emission for a large part of the dimmer setpoint range, and at some point it goes down in intensity in an erratic way. Pretty much, yes. But that is true for any non-dimmable bulb with any dimmer. We are just in the first phase of LED lighting deployment, the "compatability" phase where the bulbs are still using existing form factors of incandescent bulbs, and are supplied with mains voltage that is converted to current inside the bulb. It is not the best solution to use such bulbs in combination with existing dimmers. Of course a next phase will be to use more reasonable form factors and connection, where the electronics have a light level setpoint that determines the LED current and the mains voltage is directly applied without intermediate phase-cut dimmer. There are already dimmers made for LEDs which work well. And there are commercial systems which use low voltage to drive the LEDs. But these are all proprietary; there are no standards for LED lighting yet. Eventually, maybe standards will be developed for the commercial market, but right now there is zero push for such standards. It's going to be years (if ever) before such standards are created for the residential market. There are too many reasons to stick with 117V wiring. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/29/2014 12:28 AM, Michael Black wrote:
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. I never claimed it was a voltage regulator. You can have adjustable current regulators, also. 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 That's one of doing it, but not the only way. It probably is the most efficient way, though. And it does solve some other problems. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
On 11/29/2014 9:37 AM, rickman wrote:
On 11/29/2014 9:15 AM, Jerry Stuckle wrote: On 11/29/2014 1:07 AM, wrote: In rec.radio.amateur.boatanchors Jerry Stuckle wrote: snip How do you explain the manufacturer of dimmers says standard dimmers cannot be used reliably? Because the manufacturer wants to sell their dimmers and their bulbs. Use Phillips bulbs and there is no problem http://www.cnet.com/news/which-led-l...t-for-dimming/ snip remainder Then why do all manufacturers say the same thing? And exactly what are the qualifications of the author? A "text-based adventure connoisseur"? I'll believe the engineers who design dimmers, not the funny pages. You are being a bit silly about this. The guy did a *test* which was clearly pretty thorough, thorough enough that he could detect *and* record the flickering of the bulbs when dimmed. He pretty clearly doesn't have a manufacturer bias since the same company had the bulb that tested as the best and another which tested as the worst in the group. Unless the guy has a reputation for faking such tests, why would you doubt his work? Ignoring valid test data and preferring the opinion of manufacturers who have a clear stake in the game just seems odd. Do you deny that the tests show at least one brand and model LED bulb works perfectly well with a legacy dimmer? The guy is not an engineer - and AFAICT, has no engineering experience at all. And I don't trust ANY tests performed by untrained personnel. And all it shows is that ONE bulb worked properly with ONE dimmer. It doesn't say how LONG it worked, for instance. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
High brightness LEDs?
Jerry Stuckle wrote:
On 11/29/2014 4:30 AM, Rob wrote: Jerry Stuckle wrote: For incandescent, yes. But not for LED bulbs. If that were the case, why would some LED bulbs be dimmable and others not? "is it dimmable" refers to the use of a phase-cut TRIAC dimmer in combination with a retrofit LED bulb designed to run on mains power. No, some bulbs are not dimmable, period. Some are. None work reliably with triac dimmer controls. Maybe not in your world, but here we can buy TRIAC dimmers and LED bulbs that work together. You probably have a 13.8V stabilized DC supply in your shack. Can you use it as a variable-voltage supply by putting a dimmer in front of it? Completely unrelated. The LED electronics and the power supply work completely differently. Maybe your power supply, but mine is a switchmode supply and it works completely the same as any other. It is regulated for voltage, not for current, but that is another matter. There are already dimmers made for LEDs which work well. And there are commercial systems which use low voltage to drive the LEDs. But these are all proprietary; there are no standards for LED lighting yet. Eventually, maybe standards will be developed for the commercial market, but right now there is zero push for such standards. It's going to be years (if ever) before such standards are created for the residential market. There are too many reasons to stick with 117V wiring. LED is about current, not about voltage. A lighting system can put many LEDs in series and use a higher voltage. What is important is that the supply circuit gets separated from the bulb, so that it can be made dimmable, externally controlled, etc and the LED gets DC current supply. The mains here is 230V AC. There even are proposals to change that into 325V DC or even 500V DC. Not accepted proposals with a set date, but still. DC supply is more efficient for the home these days, now everthing uses switchmode supplies, it can transport more power with the same amount of copper and the same class of insulation. |
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