This is an easy enough circuit to build, I'll go with this one, thanks.
This is an easy enough circuit to build, I'll go with this one, thanks.
Check these out. These are current regulators for Cree high power leds.
That reminded me of something I saw at
Think I might just start looking for a high quality LED flashlight, and be done with the old one.
Thanks for everyone's help, greatly appreciated.
A much more sensible option. Make sure you get a good brand one, otherwise you'll be getting the fake asian copy LED's which aren't anywhere near as bright as the Cree or Luxeon. Ebay is chock full of the fake ones. When you see a 3W Luxeon light being advertised for $5, you know it's not the real deal. Have a look here for an excellent review site:
I just ordered one of these Cree ones for my bike (heaps cheaper than an equivalent output purpose designed bike light:
Dave.
light:
That flashlight is something. I will definitely give that one a thought. Well worth the money.
You might want to sub a low drop out regulator so it will work down to the last dregs of the battery charge.
If you are running on batteries, a switch mode current supply is a better choice (if battery life and cost are a concern). The idea is to regulate the current without producing heat with the XS voltage. A switch mode constant current supply will us a pulse width modulator to regulate current and an inductor to smooth the current to the LED. Unless you buy a ready made LED regulator, it is more complicated, but with the numbers you're looking at you'd double the battery life with a switching regulator.
But this discussion started with what resistor to use and resistors aren't efficient current limiters . . . the regulator idea wastes as much power as a resistor but protects the LED much better.
"More than one way to skin a cat" as the expression goes.
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