and assemble that with SG3524 . ( in the schematic is SG3525)
Thats also a problem right there. Look at the datasheets for the SG3524 and 3525. Although they are very similar in terms of supply voltage and operating frequency, the push-pull outputs aren't available in the 3524. This should be 'ok' if you constraucted the circuit using the totem pole transistors to drive the mosfets (which shouldn't be required if you use a SG3525). But if you're driving the MOSFET's direct from an SG3525, the MOSFET's aren't being driven correctly. Trying scoping their gates to see if they are reaching the power rails 0 - 12V.
I would suggest reading, and RE-reading the original page. **broken link removed**
This has basic details on debugging and circuit operation. Also note there are TWO versions of this circuit.
Apologies if I seem like I am being rude, or patronising, its a tough project (aren't all switched mode power supplies?) with a LOT of variables. It makes building it with anything other than the original parts very difficult. In my experience it can be a minefield, that requires careful checking of waveforms with an oscilloscope - its why I stick to digital mainly lol
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