Sunday night project...


Oct 18, 2005

It's sunday night and I'm bored. So I thought of putting a fan that I used to overclock my cpu back in the day, to work. I'm thinking to connect a usb cable to it and hence power the fan through the usb port. I know that a usb port can output only 5V, so before burning down the house, I thought I might ask before doing anything stupid.

The fan that I have is this:

Delta 80x38mm FFB0812EHE

Specifications: 80x80x38mm, 80.16 CFM @ 5700 RPM, 52.5 dBA, 10.80W, .90 amp, 12v DC, 3 pin power connectors.

As you can see, the fan it's 12v... is that the requirement or max it can go? What's gonna happen if I connect the red and black wire to the red and black wire from the usb cable?
Anyone have any ideas?



Moderator<br>Digital & Video Cameras
Jan 2, 2006
All that's gonna happen is it'll spin at a slower speed, or it may not even run. 12V is the voltage needed to run at regular speed (5700 RPM). Most fan controllers change that voltage to 7V I think at their lowest speed. 5V may not be enough to run it. Using the old Delta fan again, eh? AKA the jet turbine? God those were crazy back in the day...


Elite Member
May 1, 2001
More likely Talcite has it. Theoretically that fan will draw around 0.33 Amp at 5V which is within the 0.50 A rating of a USB port - but only if there isn't much else attached to your USB.
First you should check whether that fan will even start at 5V by connecting it directly to the 5V on a drive connector (red and black wires.).
If it does work, you won't get anywhere near the breeze you were getting with the full 12V power - but it will be a heck of a lot quieter...
I'd suggest that if it does work at 5V, you keep it connected to 5V from a drive connector to be safe. There are PCI slot plates with molex connectors built into them to bring power outside the case neatly. And similar to fit in a 3.5" drive bay. Places like and carry them.

Example of PCI slot power outlets.


George Powell

Golden Member
Dec 3, 1999
I have a couple of Deltas lying around and a quick check comfirms that they run fine at 5V. In fact they still make a hefty whine at this low voltage.