rheostat mod

[avi85]

Hi everyone!
I have a thermaltake volcano12 on one of my old computers and as you may know it comes with 2 rheostats (one for the front and one for the back).
In my current case I have this one fan which really annoys me so I decided to hook up the rheostat to that fan (wire cutters wire stripper and electric tape were all I needed) but for some reason the fan only works when the rheostat is in the last fifth or so of the dial the first four fifths or so don't supply enough current to get the fan to spin, is there any solution to this?

 

[Zepper]

If it is actually a variable resistor then it has to match the fan. What are the current or power ratings of each fan? Also some fans have a narrower working voltage range than others. Take your DMM and measure the voltage when the fan starts then so to top speed and then back off to where the fan stops again and read that voltage. Then you will have starting voltage and minimum working voltage points.

.bh.


.bh.

 

[Zepper]

Oh, thread titles ARE editable here... Or do you really need a new Ho in a Hurry.?.

.bh.

 

[SparkyJJO]

last time I did that I almost burned the thing up. I found with those Tt fans the electricity doesn't go through the rheostat to the fan but rather the rheostat controls some circuity inside which adjusts the fan. It has something to do with the rheostat being in parallel with some resistors, not series (I haven't taken one apart to figure it out, but that is how it appears to work).

 

[EagleEye]

Originally posted by: SparkyJJO
last time I did that I almost burned the thing up. I found with those Tt fans the electricity doesn't go through the rheostat to the fan but rather the rheostat controls some circuity inside which adjusts the fan. It has something to do with the rheostat being in parallel with some resistors, not series (I haven't taken one apart to figure it out, but that is how it appears to work).

If it was in series, it would be giving it more amps than if it wasn't there at all, so wouldn't it be in parallel anyways? Or is the rheostat designed not just to lessen the ampage, but to also increase it as well?