Where do I connect the fan?
Posted:
Tue Jul 08, 2014 1:38 pm
by baseballguy
Hi everyone, I recently just bought a small fan for the Parallella board, but I don't know where to connect it or if soldering is required? Where do I connect the black,red, and yellow wires? I think they are called a 3-pin Power Connector.
Sorry for my limited knowledge. I'd appreciate any help
Re: Where do I connect the fan?
Posted:
Tue Jul 08, 2014 2:01 pm
by baseballguy
Re: Where do I connect the fan?
Posted:
Tue Jul 08, 2014 7:59 pm
by greytery
The specs for the fan suggest that it's noisy @ 26.8 dBa, presumably when full-on @ 12v. This noise will be much less if you connect (solder) it to the board's 5v supply. But I'm sure you can get quieter examples if you continue to search.
Cheers,
Re: Where do I connect the fan?
Posted:
Thu Jul 10, 2014 4:49 pm
by AlbertoGP
Normally, the black wire is "Ground", the red wire is "+12V", and the yellow wire is the tachometer signal: two or four pulses per turn of the fan, to tell the mainboard how fast it is spinning.
To cool the Parallella, you need to plug only the ground and +12V wires: the fan will run a the speed proportional to the voltage, with the standard RPM if you supply the standard 12V for which this fan is rated.
If you give it less volts, it'll spin slower. That's how a computer's motherboard or fan controller can make it adapt to the temperature inside the computer.
I've looked at the specifications for that fan () and it does not indicate the starting voltage: that's the minimum voltage at which the fan will start spinning, which will be lower than the standard 12V. Some 12V fans have a starting voltage of 4.5 and can work with the 5V you can get from the Parallella board, others require for instance 8V and will need their own power supply.
In your case you'll probably have to try it out with a 5V power source.
I've put what I found out trying different fans here:
Before getting those small fans I used a 92mm 12V case fan I had at hand: I tried to power it with 5V and it worked very well, but other two 12V fans I tried at the time did not start up with 5V.