Yes, the goal is to pull pin 4 up. But how ?.... lifting pin 4 above maximum dtc voltage?
1- you can opt for a current transformer
2- use the over current opamp on the TL494
3- What kind of PSU are you making after all?
Follow this circuit it works I tried it you will have variable voltage and variable current. You can make fixed resistors instead of pots if you do not want it variable. Just omit the 4.7uf cap tied to pin 3
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you can also follow this link http://320volt.com/en/akim-voltaj-ayarli-atx-smps-guc-kaynagi-modifiye/
You could build a simple latch and monitor the current on the primary ground return(s)
any transistors should work, although some tweaking maybe required.
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