"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

In article ,
(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!!!!

Are there any 5 volt LEDs around?

http://www.oxley.co.uk/lamps/bulb_replace.html

http://www.ledtronics.com/pages/News56.htm

http://www.ccrane.com/led_replacemen...ight_index.asp

and many more.

Al

--
There's never enough time to do it right the first time.......

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!!