The cheapest mosfet anti spark switch build ever, hopefully

ok here goes after a lot of research, my chepo diy build of anti spark switch a bear bones design, no pcb!
looking for about 100amps ish, with a fuse. going to base it on vedder design seem to work ok.
3 mosphets IRFS7530-7PPBF N-Channel MOSFET, 240 A.
4.53 pounds.

This is definitely bare bones dude. You’ve literally just mentioned the words antispark. :wink:



from what i read, loop switches work quite well

Loopkey is really the only 100% reliable method.

Every antispark switch i’ve read of has had issues.
eventually one will come that works im sure

So go forth young man, and forge the way to a new era


Nothing is perfect :tipping_hand_man: 100% is a strong claim

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Heres a question:

Does anybody know the internal workings of the xt90s ? Like how does it suppress the spark?

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fitted link bars to drain and source of mosphets.
heatsink, components, and connectors to follow

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are you diode connecting these fets?
whats your schematic>

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going to use this one


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Change r2 to be 100k and add a termination resistor.

what a 10k across the zenner?

Yes. These two posts shed some light on that. Ask in the loopkey thread if you want more info :slight_smile:

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or does design work better?
sorry this one
[File]Antispark Rev3 (1) - Copy.pdf

ummmmmmmm i dont have access to your pc :smiley:


From what I understand the inrush to charge the capsitors on the VESC is what blows the anti spark and if I rember right there was a post saying that was over 1kA. Could you not just double up the mosfets to make it more reliable? Put 3 more on the back or some thing? I may be completely wrong and that wouldent work for some electronics reason.

You use an RC timing circuit to limit in rush current.

Or an expensive power resistor precharge network…

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You could potentially just stack fets intil it works.
the real problem is the lack of precharge circuitry

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Flipsky tried to stack 10 MOSFETs glued to a heatsink and it still failed.