On picture is typical connections ATX power supply drivered TL-494
I'm interested in comparator 3.
This comparator compare voltage from Error amplifier in TL494 (pin 3) integrated on C36 10nF with voltage on - input pin8 (LM-339) around 1,2V
I'm not clear what it is good for?
Looks like the comparator wireball eventually makes the
PG (Power Good) signal and one term is the FB (error
amp (-) input I expect) is somwehere sane (not railed
trying to get there, but satisfied).
Agreed - part 2 monitors the 'start/stop' signal from the motherboard.
The other sections monitor the voltages on the output lines and produce the 'Power Good' (PG) signal which eventually drives the motherboard reset line.