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Unread 22-01-2008, 00:44
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Join Date: Apr 2005
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Re: backup battery charger

yep, the circut is more than a little flawed. using about 1/3 of the parts in the schematic, I made a small variable power supply today that I am a lot more happy with. now, i just charge that battery however I want (within the margins of ni-cad common sense) and I can also use the simple circuit to power various other devices from any DC source between the desired end voltage and 30 something volts. to make the LM317T into a variable power supply you add a 240ohm resistor in between the Vout and ground pins and then connect the ground side of that to a 5k potentiometer if I remember right. look up "lm317t" in Google and you will see lots of simple power supplies like this.
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