Overwattage on a fan controller

[rsquared]

So I just got a NoiseMagic NMT-3 fan controller. It's rated for a maximum of 2.5 watts. The fan I would like to control with it is a Delta EFB1212SHE, spec'ed at 9.6 watts.

There is obviously a discrepancy here.

I ran the Delta on the NMT-3 for a minute or two, and it didn't burst into flames or anything. What would be the long-term effects of overloading this fan controller? A shortened lifespan for the controller, I would guess? If I put some small heatsinks on the controller's ICs, would that help? (Attached to that fan, there will be no lack of airflow.)

 

[BillParrish]

Short answer, yep as you noticed, it wont live long.

Long answer, I doubt that fan pulls that much all the time and since you will be automatically "throttling" it down most of the time it might last a while. The issue would be if temps got hot and the fan ran full speed for a length of time.

Heatsinks on the chips would help, and if in the direct airflow it might live, how long is anyones guess. Could run for years but I would not bet on it.

What you should do is read the part numbers off of the controller chips and look up the data sheet it may provide additional information but even with a decent little heatsink I doubt running the chip at almost 4x its rating (assuming the 2.5 W came from the chips power rating) is going to be anything but bad news in the long run. So its a crapshoot and like Vegas the odds are not in your favor. There may be other parts on the board other than the IC not rated for that kind of power output, without the schematic I have no way of knowing. So it kinda boils down to how hard the $15 bucks for the temp controller was to come by.

 

[evilcartman]

You could try that or you could pick up one of these for a cool $13 + shipping.

 

[rsquared]

I doubt that fan pulls that much all the time and since you will be automatically "throttling" it down most of the time it might last a while. The issue would be if temps got hot and the fan ran full speed for a length of time.

I also have a Delta EFB1212LE, same fan but lower-speed and rated for 1.92W---and half the airflow. I'll probably start with that and see how my temperatures and noise levels fare. But I suspect that with the high-speed high-power 'SHE, it will be moving so much air that the temperatures will never get hot enough for the fan to run at high power...

What you should do is read the part numbers off of the controller chips and look up the data sheet

Hmm. good idea. As it happens I work in surface-mount electronics. I'll take the circuit board to work Monday and avail myself of the resources there. (Well, actually Sunday night; I work third shift.)