Hi Joe,
The LEDs I'm using here are Osram E67C's:
http://rocky.digikey.com/WebLib/Osram/Web%20Data/LW_E67C.pdf
They have a very good combination of brightness and viewing angle, as well
as being small enough to fit pretty much everywhere. While the per-piece
cost is high, the price does come down decently in quantities of 100 or
more. They're 85 cents if you buy a reel of 2000 ;)
I'm going to look at putting these on the rear PCB of the tach, arrayed
around the outside edge and shining towards the annular gap. That should
take care of the shadowing problem. I tried the side-angled array shown in
the article, in the ammeter, and it was very bright all the way around.
Theo
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