1 AA - Rebel vs Cree for max output

[moses]

With a single 1.2 volts AA rechargeable cell running a LED, it seems that the great challenge is to be able to up the voltage into the 3+ volts range.

Since the Rebel has a lower Vf than the Cree, my guess is that the circuit on a single AA can drive more current through the Rebel than the Cree.

Any thoughts on this?

Thanks,
Mo

 

[kaidomain]

Most good AA step up circuits are able to hold voltage above 3V+ fine.

Yes, you can drive more current than on a Rebel than a CREE, although not by very much. Since a bag of CREE LEDs are not categorized with VF, we have to hand pick the smaller VF ones for 1AA, and higher VF for Li-ion driver.

See here:
http://www.molalla.net/~leeper/rebel.htm

 

[lctorana]

I know it's all about constant current with LEDs, but that's fascinating.

Thanks Kai!