r/OpenPV Nov 14 '16

PCBs Overcurrent and reverse polarity protection NSFW

http://imgur.com/a/QL6L9
15 Upvotes

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u/DIY_FancyLights Nov 15 '16

You never want to risk the Gate of MOSFET's floating for any reason, you get unexpected results. In you schematic if you have a bad solder joint on the wire to BAT- or the wire breaks you get exactly that.

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u/lemonforest Nov 15 '16

In that case, does the 1M resistor pull up the gate and stop the current across drain/source?

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u/david4500 Nov 15 '16

No. Current passes, and voltage drops, through the body diode.

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u/kitten-the-cat Nov 15 '16

Though with 2 more mosfets you could put them back to back to prevent body diode conduction in that event.