What are the 2 POTS for?

[ChaoZ]

I am looking into an old PSU of mine, old delta atx 300W-KB1.

I remembered that calibration of the pots are possible for the various voltages.

I found 2 here, Pots-A for the 12v+5v, but I dont know what is the POTS-B?

Not 3.3(fixed), not the 12v nor 5v using the 2nd pots.

Anyone knows?

Thanks!

[Sparky]

Re: What are the 2 POTS for?

adjustment for the fan ramp-up temp?

[Harvey]

Re: What are the 2 POTS for?

Could be for current limiting protection or overvolt protection.. or almost anything to be honest.

[999999999]

Re: What are the 2 POTS for?

Trace the circuit to see what the pot's connected to, or, just leave it as-is, if the PSU works ok there is no need to adjust it?

[ChaoZ]

Re: What are the 2 POTS for?

This PSU does not use fan-rpm-management.

I checked on the voltage again, this POTS-B seems to control a voltage between 2 to 4 volts. It leads into a LM339D chip.

Not sure what it does, but is it to control the PS-ON or PWR-ON signal?

<- reading atx spec-sheet

[999999999]

Re: What are the 2 POTS for?

Suspect it's part of the OVP shutdown circuit, unless you had a very light -> no load and this was shutting PSU off, it is best left at it's present adjustment.