On Sat, 29 Oct 2005, Steve TR wrote:

http://216.110.197.146/led_design.gif

The drawing is not perfect and the device doesn't need to be exactly like
this, but just a flat panel around 3 to 4" high and roughly 6-10" long.

Your individual emitters designated as tail or brake: Wrong way to do it.
You really want all your emitters to be active in both modes. There are
readily available PWM circuits for the dim "tail" mode, and then you just
shoot full power to 'em for the bright brake/turn mode.

http://www.pmlights.com/products.cfm?cId=1&fId=57 (The one I'd recommend
is the 36-emitter unit P/N M417RP he
http://www.pmlights.com/products.cfm...Id=57&pId=1478 ) They're 4"
round, and you could simply line 'em up side by side by each, spaced about
3/4" or so away from the inner surface of the car's lenses. Dual-intensity
capability built right in, on all emitters, and these guys are BRIGHT.

To reduce the appearance of discrete circular areas of light, I'd obtain
some diamond-pattern fluorescent ceiling light diffuser material and place
a single thickness of it right up against the inner surface of the car's
lenses.

If you gotta have rectangular, there is an LED Model 45 from Truck-Lite.
3-13/32" by 5-5/16", P/N 45252R, e.g.
http://www.imperialinc.com/items.asp?item=0812540 (Truck-Lite's own site
is down at the moment).

These "full-pattern" items cram-packed with emitters are the better way to
go, compared to the units which use fewer emitters (5 to 8, typically)
with fresnel optics to spread the light.

(Sure, it can be fun to start from scratch using nothing more than
perfboard and raw LED emitters, but the optics make a real problem -- they
cannot effectively be crafted in your workshop -- and these modules are
inexpensive enough that you can pick 'em up, install 'em, and then move on
to other things.)

You will need a different turn signal flasher. I recommend an Ideal EL-12C
electronic heavy-duty plug-in flasher. Nice loud click, and it won't care
that the load has suddenly got a lot lighter. The stock flasher won't
work, because it is load-sensitive.

For your next trick:
http://www.danielsternlighting.com/t...ys/relays.html and
http://www.danielsternlighting.com/products/csr.html

;-)

DS