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Phil Gardner Phil Gardner is offline
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Default Ni-MH variable current supply charger

On Mon, 15 Oct 2007 21:55:23 +0000 (UTC), "Jim Backus"
wrote:

On Mon, 15 Oct 2007 15:02:15 UTC, Phil Gardner wrote:

HI
Just bought 4X 2700mHa Ni-MH AA battery's my old charger is not up to
charging these in a reasonable time C/10 so im looking to build my own
charger.

I have a 1.5 amp power supply what I need is a variable current
circuit add-on- about 150-800 mA but cant find anything Simple! as in
DIY simple.

Any thoughts, suggestions?


LM317 voltage regulator IC set up for constant current.

Googling on "LM317 constant current" produced this:

http://users.pandora.be/davshomepage/current-source.htm

remember to mount the regulator on a heatsink - a square of 1/8 inch
aluminium a couple of inches square should do the job



Thanks but the problem with the 317T and also the L200 is R=1.25/I
Fine for a fixed current but hard to achieve a variable one.