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Unread 21-06-2016, 20:03
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Re: SD540 Motor Controller

17 mOhm Rds on is really high for this type of motor controller. At 30 amps, which FRC robots will draw for a few seconds, you're dissipating 15.3 watts in your FETs!

It seems weird to have this so high - you'd almost have to go out of your way to find FETs with 8 mOhm Rds. There are tons of FETs designed for motherboard switching power supplies that do much, much better. It seems more likely there's some other issue, like V_gs dropping on the high side FET, or insufficient gate current, or possibly even thermal issue.
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