LiPo charging circuit advice

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pneumatic
 
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Joined: Sun Jul 26, 2009 3:59 pm

Re: LiPo charging circuit advice

Post by pneumatic »

It's the same part number as the P mosfet at P3, which is what's allowing the 12V

Vg = 12.3V
Vd = 12.3V
Vs = 11.8V

Maybe I fried it because I wasn't static safe when handling it?

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pneumatic
 
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Joined: Sun Jul 26, 2009 3:59 pm

Re: LiPo charging circuit advice

Post by pneumatic »

Well, I tried swapping in one of the other P mosfets into that position (the one from P2, one one controlling the charger power), and it behaved the same way. So, either the circuit isn't behaving as expected, or I've fried both of those mosfets.

Either way, I've run out of time to debug this, and I'm going to fall back on using a couple of schottky diodes. I've found some that are rated for 3A, and a couple that are rated for 8A, and I think they should do fine. According to the datasheet, the Vf(max) on both is around 0.4V, and I've measured it with my DMM as about 0.22V, so that should be acceptable.

Thanks again for all the help.

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adafruit_support_mike
 
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Re: LiPo charging circuit advice

Post by adafruit_support_mike »

Sorry it didn't work for you.. I'll have to a version and poke at it with the 'scope.

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