Mike,

Thanks for the tip - sounds like a great mass-market idea.

How about a light that will take one of anything 1.2v to 3.8v, N cell to D cell, including CR123 and Pila cells? It would be hard to do that efficiently with 1 or 2 cells, since the potential voltage range would be about 0.9v to ~ 8 volts, but it's feasible with a single cell ranging from 0.9 to 4. Red or yellow LED would be not too hard; white-blue-green I'm not sure, but I think that is feasible as well.

The guys in CPF could whip this up; the mechanical part is not hard; just some thinking (I already did) and machining (won't do unless the electronics are designed/available).

A cheap set-up that could handle any common set-up (N to D, 1.2 to 1.5 volt) and with a little fiddling, a 3 volt CR123, could be based on the Dorcy AA LED flashlight electronics package set in a custom machined body. Hmmm... that just went on my list of things to do... I already have a couple of "donor" Dorcy single AAs I bought just for tearing apart anyway...

The sweet spot for usefulness is probably AAA, AA, C, and D in both rechargable and dry cell formats, I suppose. That should be pretty simple. I already have a couple of "donor" Dorcy single AAs I bought just for tearing apart anyway...

<grumble> another project... but thanks for the idea! I think this has "Christmas gifts" written all over it...

Regards,

Tom