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i am tested with 12v dc and 500Ma current adapter. then the output voltage is 33v acThe transformer magnetizing current is proportional to the average value of it's input waveform, not the RMS.
This means a 12.6V square-wave (from a lead-acid battery) causes about a 16% higher transformer magnetizing current than a 12Vrms sinewave voltage, which may be saturating the transformer.
Try operating the circuit from about 10Vdc and see if that makes a difference.
can you tell in more detailed?The only thing limiting the current through the FETs is the impedance of the transformer. A 5 A rating does not mean that the current through the winding is limited to 5 A. You do not say how hot the FETs are getting. Can you post a scope shot of a FET drain voltage?
ak
So you don't have a 10Vdc supply you can test with?i am tested with 12v dc and 500Ma current adapter.
That resistance only effects the gate signal rise and fall times, it has no effect on the final gate voltage.because a 4017 has an internal impedance comparable to the gate resistor value, its output voltage will be considerably less than its 9V supply voltage,
i don't have 10v dcSo you don't have a 10Vdc supply you can test with?
Double-check all your wiring including the transformer.
Of course. But I don't think the high dissipation he is seeing is due to slow MOSFET gate rise and fall times @ 50Hz.but the rise and fall times would be shorter with a lower-impednce driver.
Did you double-check all the connections, particularly those to the transformer?i don't have 10v dc
no, Does that even matter ?Do you have thermal paste between the FETs and their heatsinks?
i am checked all wirings all are connected good.Did you double-check all the connections, particularly those to the transformer?
But are they all connected to the correct terminals?i am checked all wirings all are connected good.
That could be a problem with a 12V transformer.i am testing with a lead acid battery which has 13.5v dc output
when i testing with that bettery the positive wire was burning both battery and transformer a little bitBut are they all connected to the correct terminals?
That could be a problem with a 12V transformer.
That's why I suggested the test with a lower voltage.
Sounds like there is a wiring error or something is shorted.when i testing with that bettery the positive wire was burning both battery and transformer a little bit