# USB power supply



## Gaurav1993 (Sep 5, 2009)

Hi
my electronics project for school was to build an alarm clock. i have finished programming it all i need now is a power supply. i am thinking about a USB power supply. i also want to add 3 re-chargable AA batteries so it can run when its not connected to a pc and when it is connected the batteries get charged. i am using a atmel m16 chip which requires 5v and when my lcd backlight is on full brightness it uses 100 mA. it would be really helpful if someone could provide a schematic give me instructions on how to build it.
thanks


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## Gaurav1993 (Sep 5, 2009)

just realised i need 4 Nihms to run the chip.....and 5v isnt enough to charge them


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## pat mcgroin (May 1, 2009)

Do you have a firwire connection? It can supply up to 30Volts.


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## askij (Sep 28, 2010)

Let me know if you build it. I need it too


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