Metealp97
Turkey
Asked
— Edited
hi i am using a 12v power supply with my ez-b i started to get i little hot so i bought a 5v cooling fan for ez-b but my fan has 3 pin instead of 2 it has an extra signal wire does this make any diffrence i am thinking of connect fan to lets say d1 if i write set(d1,on) it should turn the fan on right?
Ignore the signal wire. Just connect red to vcc and black to ground.
Further information is here
hi,
why what happens if i connect it thanks for the response
The third wire is the "Tacho" used in PCs so the motherboard can measure the speed of it. It generates 2 pulses per revolution so that the motherboard can "read" the RPM. It is not a control wire.
oh thanks then i will just connect black and red
Rich,
Any way to read that pulse and use it with EZ-B? Output a tach reading?
I was thinking that as I was typing what it's for. At the moment I have no idea and I don't have one to check either (unless an old PC has one still in it which I doubt). AFAIK it's just a 5v pulse (or whatever voltage is feeding the fan), but if the fan is spinning at 1,000rpm (admittedly that's fast for a fan) it means it will receive 33 pulses per second (if my maths done in my head is correct, it may not be), the EZB benchmark showed mine can only read/write 25 times a second.
It also makes me wonder why anyone would want this information.
FYI 4 pin fans have PWM control on the fourth wire if you wanted control over the speed.