I finally figured out how to GPSDO my rubidium oscillator so I'm going to make an extra box that contains the GPSDO, RS422 to TTL serial, and a fan controller.
I'm going to sense the temperature using an ADC and then adjust the PWM of fans accordingly in an attempt to keep the temperature stable. It will be a 5V project, but I will have 24V available as well.
Should I use a 5V or 24V fan? I think I could use a 24V fan if I used a high or low side driver although I don't recall exactly which one without looking it up!
This is a one off project, should I use a transistor to switch the fan or a mosfet? What calculations do I need to do to make sure the device will not overheat?
Digikey has 60mm square fans from:
5V - 0.4W to 1.75W
25V - 0.72W to 10.3W!
I don't think I need any sort of beefy fan though...