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Old 10-10-2009, 12:47 PM   #2393 (permalink)
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Originally Posted by jackbauer View Post
The following takes place between 4pm and
In regards to the gate ringing, I wonder what the drain-source voltage waveform looks (or whatever the igbt equivalent is- collector emitter?)

I notice that you have some significant legth of wire between your caps and igbts.. I had a similar setup when I was playing around with a charger and found excessive ringing on the Vds turnoff. When I asked the evtech list about it, they pointed out that the current in that length of wire goes from zero to max with every swithing cycle. Any inductance in that wire will cause voltage ringing, even if it's just the parasitic inductance of the wire itself. They suggested to minimize the lenth connectio between input cap, switcher, and rectifying diode to reduce ringing, and it solved the problem.

So, it might be that the gates are picking up some noise, or maybe the gate wire connnections are long and their parasitic inductance is contributing (they also recommended to keep those short)

Anyway, some things to try if you haven't found a solution..
ReVolt AZ testing thread:
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