Hello:
I used UC2843 to make a 50W forward power supply, input 40V, and output two positive and negative 12V.
The short-circuit protection circuit is conventional. Take the CS pin voltage into the positive terminal of the comparator, and REF is divided into the negative terminal of the comparator. When the CS detects that the primary current is too large, the comparator output is positive, and then the COMP terminal is pulled down through the triode. Turn off the PWM.
The dynamic state of the circuit grows, and the normal temperature and high temperature short circuit protection is normal, but at low temperature, the primary MOS is damaged when the short circuit is protected.
Excuse me, how can I troubleshoot?
Thank you.
