Finding a decent fan with a speed wire is hard. Any ideas how to build one on? I'm toying with the idea of a Hall sensor glued to the fan stator body, picking up changes in magnetic field, cleaning up the signal and sending it via the mobo header to MBM5. On a side note, my Panaflo L1A came untailed with 2 power wires. There's an unused tag, labelled "S" that shows 12v when the fan is running. Am I being over-optimistic in thinking there might be some working speed electronics already fitted?
umm most good sites will offer the fans in 3 or 4 pin versions. If not, you can pick up 3 pin wires from pcmods for (.99?). I know they have them in the store but I dont think they do online.
See what you mean. OCS sell the ready-made connectors, just pull the 2-wire untailed connector off the fan and push on the new one. But if they're like the ones Directron sell in the States they're only 2-wire, no speed. All of which strongly hints the fans don't have speed sensors installed.
My dim understanding of brushless fans leads me to think that they have the Hall effect sensor in order to do their commutation (or whatever they do instead), so I think you have a sensor output, it's just not necessarily wired to anything. Two pulses per rotation is what I recall.
Some people say some Panaflo fans have speed sensing, others don't. I built myself my own Panaflo 3-pin tail with speed sensing and nothing shows up on my motherboard at all. I tested this with only two fans however, too lazy to test on my other eight Panaflos.
Here you go, linear, one good link deserves another Sensors - June 2000 -Solving Cooling Fan Problems with a Smart Sensor
