Lamptron FC5 fan controller, only runs fans at full speed?

grimbo

Reputable
Jul 13, 2014
2
0
4,510
I don't know if this is normal, or whether I have a faulty controller.

I've got a selection of different fans all connected up to the fan controller, 2 scythe gentle typhoons on a rad, a noiseblocker eloop on exhaust, and a larger 200mm NZXT fan on intake. It's a 650d so intake fans are pretty limited :/

As soon as I turn the dials on the controller, the fans just go straight to their full speed, 1440 for the scythes and 1200 for the noiseblocker. Even if I turn the knobs right to the very lowest setting, they might flicker at a lower rpm but then slowly pick up to max speed.

I bought the fan controller so I could slow the fans down when I'm not gaming to reduce noise. But I can't seem to control their speed at all. They're not PWM fans, but the lamptron fan controller only accepts 3 pin fans anyway so I can't see that being the issue.

Any input would be useful.

 
Solution
If you have a voltmeter, measure the voltage the fan controller provides at various speeds. If the fans are 3-pin, then the only way to moderate speed is to regulate the voltage. SO measuring the voltage will tell you if the fan controller is defective.
If you have a voltmeter, measure the voltage the fan controller provides at various speeds. If the fans are 3-pin, then the only way to moderate speed is to regulate the voltage. SO measuring the voltage will tell you if the fan controller is defective.
 
Solution

grimbo

Reputable
Jul 13, 2014
2
0
4,510


I popped my voltmeter on all the terminals one by one, and they do drop voltage from 12v but only for the first 2 degrees of the turn, then it's straight to 12v. So trying to slow the fan speed you have to literally do turns finer than the width of a hair. Must be a dodgy controller, which is annoying because I bought it about 6 months ago and can't return it now.