There's my universal smps from parts from pc power supply.If it don't start to oscillate,reverse feedback windings (15k resistor).I'll test it on some amps,and it works great.PCB is without rectifier,I'll finish it later.
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Question: EE33 transformer is from pc power supply too ? don't they have more like 3.3 / 5 / 12 V output rather than 28/0/28 ?
Resistors or reverse connected diodes seem to be missing between B and E of the transistors (unless they are integral to the components used).
Without them, the charge on the coupling caps cannot be reset, and the converter will only be able to provide a small output.
Without them, the charge on the coupling caps cannot be reset, and the converter will only be able to provide a small output.
This is not right,i tested it,with diodes it doesn't working properly,(smaller frequency and dead time,transistors blow up)
Then the charge balance is ensured through some parasitic mechanism, probably B-E breakdown. The 330K's are much too large to provide the average base current.
with no feedback... whether the drop voltage will not happen?
or...how your suggestion
regards.
Drop will happen but if you make a good transformer... drop was smaller than 50hz transformer on heavy load.
