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"Fred Nachbaur" wrote in message
news:xe33b.61864$K44.43700@edtnps84... That being said, there *is* an LED rated for operation directly from a 5 volt line. Unfortunately, it's a flasher. Either blue or while LEDs have pretty high voltage. Of course, they require current limiting, which requires an overhead of voltage... Tim -- In the immortal words of Ned Flanders: "No foot longs!" Website @ http://webpages.charter.net/dawill/tmoranwms |
To all who suggested LEDs, thanks for the suggestions but there is a
problem. These are not pilot lamps. They illuminate an LCD and need to be controllable by a regulator circuit for intensity. LEDs aren't really suited to this application, although some modification of the circuitry and optics might make it work. All I want to do is get some more incandescent lamps for this radio, and keep it close to original. Bob |
Lizard Blizzard wrote:
Bob wrote: Looking for tiny incandescent lamps for my TM-451A Kenwood. Apparently these are 6 V or so; there are four of them in series parallel controlled by a regulator to vary intensity. They light up the LCD and two of them are burned out. I have searched many of the usual sources and can't seem to locate replacement lamps; as a last resort I could go to Pacific Parts but they are so expensive. These are just inexpensively made tiny bulbs with wire leads. Any suggestions? The 272-1140 6V lamp from Radio Shark should work, if they still stock it. They have them. I just bought a pack a few weeks ago. - Mike KB3EIA - |
"Sven Franklyn Weil" wrote in message
... In article , Lizard Blizzard wrote: Are there any 5 volt LEDs around? Indeed there are. Check for panel lights or LED panel illuminators in any good electronics catalog- they come in lamp style mounts. The units have multiple dice inside and the proper dropping resistor in place already. Cheers! Chip Shults My robotics, space and CGI web page - http://home.cfl.rr.com/aichip |
Bob wrote: All I want to do is get some more incandescent lamps for this radio, and keep it close to original. email JKL Lamps and ask what they've got to meet your specs. If they don't have it - you're in trouble- they have several THOUSAND types available. You do have to go through one of their distributors - but they'll tell you who has the lamp you want. You're going to need to measure the bulb very carefully length & diameter - is it round or cylindrical; wires out the bottom (standard) or each end (axial)... and you're going to need the voltage and current of one bulb. JKL has wire base bulbs in 5 and 6 volts from T-3/4 size (.187 Long X ..094 diameter( to T-1 3/4 (.520 long X .230 diameter)... the T-1 1/4 standard size come in 5V @21, 40, 60, 75, 115ma - 6V @ 40, 60, 200ma 6.3V @70 & 200ma - life ave 10,000 - 100,000 This is the bunch that the has "fuse clip" bulbs in 6.3, 8 and 12V email: best regards... -- randy guttery A Tender Tale - a page dedicated to those Ships and Crews so vital to the United States Silent Service: http://tendertale.com |
Sven Franklyn Weil wrote:
In article , Lizard Blizzard wrote: eventually burn out, too. So it would be wise to do the right thing and replace them with LEDs, and they will last tens of thousands of hours. I replaced a grain-of-wheat lightbulb for a clock-radio dial with one from Radio Shack. The supply voltage is 5 volts so I bought a 12 volt bulb. Imagine my surprise when these damned things are only rated for 15 hours!!!! Well, the life of a bulb is roughly (rated voltage/operating voltage)^6 so (12/5)^6= 191 * 15 hours = 2865 hours. I'd call these 5V bulbs myself.... |
But the light output goes down with at least as strong a function, I
believe. So although you can greatly extend the life of a bulb by reducing the voltage, you also greatly reduce the light output. And without nearly as much of a reduction of the input power. So you end up with a dim, very inefficient bulb. That might be ok for some applications (say, if it's at the top of a tower where it's a really major pain to change) but not others (like all the bulbs in your house, unless you love to pay that electric bill). Roy Lewallen, W7EL Robert Casey wrote: Well, the life of a bulb is roughly (rated voltage/operating voltage)^6 so (12/5)^6= 191 * 15 hours = 2865 hours. I'd call these 5V bulbs myself.... |
In article , Robert Casey wrote:
Well, the life of a bulb is roughly (rated voltage/operating voltage)^6 so (12/5)^6= 191 * 15 hours = 2865 hours. I'd call these 5V bulbs myself.... Rob, I'm probably being dense but I don't follow the math. Then again I was never really good at math. what is the ^6? Elevated to the 6th power? So is this bulb going to last a while? P.S.: If it blows in my lifetime I'm not replacing it again. The only reason I did so the first time was because the original had blown its glass envelope (I _don't_ know why). Yikes!! -- Sven Weil New York City, U.S.A. |
Sven Franklyn Weil wrote:
In article , Robert Casey wrote: Well, the life of a bulb is roughly (rated voltage/operating voltage)^6 so (12/5)^6= 191 * 15 hours = 2865 hours. I'd call these 5V bulbs myself.... Rob, I'm probably being dense but I don't follow the math. Then again I was never really good at math. what is the ^6? Elevated to the 6th power? So is this bulb going to last a while? That's right. P.S.: If it blows in my lifetime I'm not replacing it again. The only reason I did so the first time was because the original had blown its glass envelope (I _don't_ know why). Yikes!! |
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