OT-sortof: Replacing incandescent panel lights
Roy J. Tellason
rtellason at blazenet.net
Sun Jan 1 17:28:39 CST 2006
On Sunday 01 January 2006 03:19 pm, Chuck Guzis wrote:
> While not directly germane to vintage computers, I can see that this might
> have some real interest for those restoring old displays.
> I've got an old (1990) 120w-per-channel receiver in which I've just
> replaced the hybrid power amp module--I think I can expect another 15 years
> or so of life out of it. What bothers me is that some of the incandescent
> 12vdc back-of-panel lamps are starting to go.
> They're soldered onto small PCBs and are the small 25 ma variety. They
> illuminate the back of small LCD displays that have an orange filter on
> them, so the color is basically that of an NE2 neon.
> I was thinking of replacing the lamps with high brightness LEDs and current
> limiting resistors--since the bulbs are paired up, I'd put the 2 LEDs in
> series with a single resistor.
> Now for the questions:
> 1. Has anyone tried to do this?
> 2. Will LED's have sufficient brightness and dispersion to substitute for
> incandescents in this application?
> 3. What would the best LED to use?
I carry the yahoo "amateur-repairs" list here, and that topic comes up fairly
often -- apparently folks are doing it, all right, but in those cases
mostly for meters, and wanting white light are using white LEDs. Orange
filter? Use orange ones...
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