Fred, just looking back at your post, I assume these are not regulators but straight MOSFETS since you took them out of a dead ESC? As such they presumably are just acting as a dropper really. What values of resistor did you use to make them run in linear mode?
Lindsay's comments about using these with slower fans and ambient temperatures make sense. For most of us, unless we are really pushing them to deliver the full output I suspect a slower air flow is entirely adequate and the PS will be protected against overtemp I'm sure. In summer it can get over 40C /140F here like in the Southern US though and I think I will investigate the switched fan option just for the hell of it. Most of the effort is in taking the PS apart and you have to do that anyway. Running two wires to add a relay and one of these temp sensors across the dropping resistors is not much extra effort (and you could just have a manual switch to short out the dropping resistor for a two speed fan if you wanted real simple).
Agree with others - this has been a nice thread. Almost no noise and self importance, just information. How often does that happen!
Originally Posted by flarssen
I have now done the mod on all three PSU's. All parts were taken from a fried 18A ESC that had four regulators in total, so basically free.