Accessing the RPM sensor on a pc fan
posted Apr 26th 2007 10:51pm by Will O'Brienfiled under: misc hacks

This one is almost too simple, but it might come in handy. It turns out that Pabst fans (and probably several others) already have the circuitry for RPM monitoring. Pop it apart allow pcb access and add your own RPM sensor lead to the PC board. Not all fans will have it, but it’s a safe bet that it’ll have an RPM sensor instead of a rotor lock indicator on the common PC board component.








This is the worst hack I have ever seen on hackaday.
Honestly, start showing knitting techniques. Most ATX fans already had a 3rd wire. This tutorial was just adding a 3rd wire. WOW! YOU CAN SOLDER 1 WIRE!
and for the pinout: Googled:”ATX fan pinout”,first thing:
http://www.interfacebus.com/ATX_Motherboard_Fan_Connector_Pinout.html
Shows the pinout of the ATX fan plug that is on every $5 computer fan out there. And yes, IT HAS SENSOR PIN!!!
If he said how to read the RPM of the fan accurately without a PC, that would be nice.