Triode
Well-Known Member
I'm curious if there is something here I'm missing. For my electric racer team, I designed a reverse polarity protection circuit almost exactly like this one on a 24V line. If the image doesn't show up, it's a P-channel MOSFET with a 10k resistor connecting the gate to ground, and a 10V Zener on the output to protect the diode from exceeding the Vgs of 20V. The Vth to switch is 4v.
**broken link removed**
Everyone who looked at it said this was "over-complicated" and to just use a diode to short reverse voltage. My argument would be that this shorts the power back to the battery. At that point, if the diode can take enough current to protect the circuit it is short circuiting the battery. I can put a resettable fuse on the line, but then how is it more simple than this p-channel MOSFET solution? I like that the fet doesn't just short out the voltage, it blocks it. But maybe I have the concept wrong.
**broken link removed**
Everyone who looked at it said this was "over-complicated" and to just use a diode to short reverse voltage. My argument would be that this shorts the power back to the battery. At that point, if the diode can take enough current to protect the circuit it is short circuiting the battery. I can put a resettable fuse on the line, but then how is it more simple than this p-channel MOSFET solution? I like that the fet doesn't just short out the voltage, it blocks it. But maybe I have the concept wrong.