Mastodawn

Currently in the process of designing the main power switch for #Torquee.
It needs to switch the 48V battery voltage at up to 500A.
I'll be using a EV200/GV200 contactor for this.
But I need a 12V supply and pre-charge circuit so I don't explode the contacts when trying to instantly charge ~8mF of input capacitance of the 2 #startergenerators to 50V in microseconds :D

So I'm designing this PCB, that'll screw on top of the cable lugs and connects to GND and actual switch input.

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LeoDJ

My planned approach is using a P-FET with a RC network at its gate so it does the pre-charging over a few 100ms in its linear region. What do you think?

I've simulated it in LTSpice and it seems to work ok and stay in the safe operating area of the given MOSFET.
(I've chosen a similar FET in LTSpice for a good model)