- Joined Nov 8, 2016
Your symbols show IGBTs - they're much slower than MOSFETs, but with a 20mS horizontal scale; that shouldn't be causing any problems.Hello.
I have designed and made my own three-phase inverter and I am currently testing it with a regulated DC supply, but recently one of the MOSFETs failed.
note: My MOSFETs have internal body diodes.
I replaced the MOSFET and checked the gate signals with a scope.
When I checked the signal on the bottom MOSFET gates, I see a constant PWM signal of 12V, independent of the DC supply, which is good.
When I look at the signals for the top MOSFET gates, the peak voltage PWM keeps rising when I rise the DC supply!!
I got almost to 20V peak with 10V DC supply.
20V is the maximum gate to source voltage so that's why the MOSFET died the first time.
So, my question is, what could be the reason the gate voltage keeps rising?
Thanks in advance.
Zeners are specified by clamp voltage and power rating - 12V should work OK.It was just to illustrate the inverter, I am using MOSFETs.
What exactly do zener diodes do? Do they limit the voltage at 12V?
What zener should I get?
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