Thermally controlled fan - convert to fixed/manually variable

[Darren]

Hi

I have a thermally controlled 120mm fan. It's an Antec 120mm Smartcool.

It has a thermister which protrudes about 2.5cm/1" from the the bearing, on
a slight angle into the case.

It spins at about 1100rpm max. It's too far from the heat source, 'miles
away' and I need it to spin to its max of about 2000rpm.

I was thinking about replacing it with a resistor/variable resistor but
wasn't sure of the resistance required.

What do you think? Any resistance? Boom boom.

Thanks

Darren

 

[Sam Goldwasser]

Hi

I have a thermally controlled 120mm fan. It's an Antec 120mm Smartcool.

It has a thermister which protrudes about 2.5cm/1" from the the bearing, on
a slight angle into the case.

It spins at about 1100rpm max. It's too far from the heat source, 'miles
away' and I need it to spin to its max of about 2000rpm.

I was thinking about replacing it with a resistor/variable resistor but
wasn't sure of the resistance required.

What do you think? Any resistance? Boom boom.

The most common thermistor is 10K ohms at 25 degC but it's a simple matter
to measure it and simply experiment with a pot.

You can also put a pot in parallel with the thermistor which will effectively
shift the operating point for any given speed to a lower temperature because
the controller will think it's warmer than it is.

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