I
Ignoramus23281
- Jan 1, 1970
- 0
I built a paralleled full inverter based on H bridge
confuguration. With all kinds of gate resistors, semikron SKHI 23 gate
drivers, etc.
I hooked everything up properly as I think things should be. The only
exception of the snubber circuit. Instead of the welder, I use current
limited under 1 Amp DC power supply set at about 14 volts.
Unfortunately, the system does not work properly and the bridge makes
DC instead of AC. Something is not right and I will try to trace
it.
On the other hand, if I turn off the power to the gate driver circuit,
the bridge stops conducting. Thats a good sign. I suspect resistance
in the pulldown resistors for the comparator (that makes inputs of
Semikrons) is too high and not enough to reliably send semikrons the
signal to switch. Right now I use 1k resistors on 15 VDC power. That
was enough for one Semikron 23, but possibly not enough for two.
I will try 400-500 ohm instead.
i
confuguration. With all kinds of gate resistors, semikron SKHI 23 gate
drivers, etc.
I hooked everything up properly as I think things should be. The only
exception of the snubber circuit. Instead of the welder, I use current
limited under 1 Amp DC power supply set at about 14 volts.
Unfortunately, the system does not work properly and the bridge makes
DC instead of AC. Something is not right and I will try to trace
it.
On the other hand, if I turn off the power to the gate driver circuit,
the bridge stops conducting. Thats a good sign. I suspect resistance
in the pulldown resistors for the comparator (that makes inputs of
Semikrons) is too high and not enough to reliably send semikrons the
signal to switch. Right now I use 1k resistors on 15 VDC power. That
was enough for one Semikron 23, but possibly not enough for two.
I will try 400-500 ohm instead.
i