Since the MOSFET driver IC (IR2110/2113) is such a critical part of the whole ckt., I think that current-boosting their outputs with NPN/PNP drivers is a very good idea, especially when trying to drive MOSFETs with really BIG gate capacitances.
Steve
Steve
It's the wrong type of optocoupler (linear, too slow) and the wrong end of the transformer to place it (switching node with high dV/dt. Something like a couple of 6N137 placed in the other (non-switching) end may work.
trafo at correct side
I tried a current sense trafo (1:~100+100 relation I think) from AT psu. My new PSU output +-35V and at 300W I measure 7VDC at zener cathode at protection circuit. Idle (fix load of 2.2W) VDC at zener cathode is 2.2V.
Aparently all ok, but when I tried to conect the 300W load after PSU is ON (no soft-start) mosfets exploded!
LOAd was 18 residential lamps 100W@220VAC in parallel.

I tried a current sense trafo (1:~100+100 relation I think) from AT psu. My new PSU output +-35V and at 300W I measure 7VDC at zener cathode at protection circuit. Idle (fix load of 2.2W) VDC at zener cathode is 2.2V.
Aparently all ok, but when I tried to conect the 300W load after PSU is ON (no soft-start) mosfets exploded!
LOAd was 18 residential lamps 100W@220VAC in parallel.

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