I have tons of power supplies, almost all ATX or server smps, but it seems that ALL have some sort of OVP circuitry on them that only allows certain voltages. I have a power supply that has an adjustable POT where I can get 11.5-13.7v before it goes into OVP mode. I need to get a little bit more out of the supply and would like to get 14-14.4 max (ideally running car voltage).

I've attached a file of the board that has the pots and possibly the OVP. Is there a way to locate the OVP circuits on these supplies and others? Once located, is it best to alter it or bypass it?

 

The smp chip has a built-in under/over voltage protection comparator for the three voltages, 3,5,12v, Or it uses an op amp comparator and fixed reference voltage, you need to find the datasheet for the chip first.

Look at these chips, Wt7520, AT2005, TL494, Sg6105a