James, On Saturday 09 September 2006 05:01, James Knott wrote:
Per Jessen wrote:
Basil Chupin wrote:
Ok, if you want me to call it a "speed controller" rather than a rheostat then to make you happy I'll call it a "speed controller" :-)
Personally, I'd prefer potentiometer. I had to go lookup what a "rheostat" is :-)
Either is a physical device, that changes resistance. I doubt either would be used in a computer for controlling fan speed.
Doubt is fine, but in this case you're wrong. My X-SuperAlien case has three of these, two on the front panel controll the four cabinet fans and the two hard drive bay fans, resp., plus a third on the PSU controll its intake and exhaust fans. It's all manual with no feedback from any sensors. It's certainly less than ideal, but I had a hard time finding a cabinet with enough cooling, enough drive bays and a big enough power supply. I ended up with a case with a big window, fans with blue LEDs and fluorescent cable sheathing. When my niece first saw it, she thought it was an aquarium! Fortunately, the CPU-mounted fan is controlled by the main-board sensor circuitry. I know I don't have the cabinet fans on high enough when I start to hear that fan.
Incidentally, a rheostat is a variable resistance, connected in series with a load to control current. A potentiometer is a variable tap on a resistor, usually used for adjusting a voltage level.
Yeah. We got that. There're probably more than a few EE types here (probably including some of us erstwhile EE types now doing software 'cause of the hideous math the make the EEs learn!) Randall Schulz