Reduce Fan Speed With Resistor

Designed with a resistor on the cable.

Reduce fan speed with resistor.

Use the 3 pin cable to connect the power supply to your cooling fan it will reduce the speed of the fan and cut the noise output dramatically. 3 pin male to female. Emmawatsun sep 20 2018 6 48 am in response to rayjai you should put a big size resistor on the 5 volt side. The only thing that has to be done is to connect a resistor in series with the power supply of the fan.

So to achieve a voltage drop of 5v we would need a resistor with value of 42 ohms and capable of dissipating 0 6w of power. Quite practical and useful. Quite practical and useful. Designed with a resistor on the cable.

Use the 3 pin cable to connect the power supply to your cooling fan it will reduce the speed of the fan and cut the noise output dramatically. If the motor draws constant current then the resistor will drop a constant voltage and the motor will run at a fixed lower speed. Ecm motors typically offer all the same speed adjustments as psc s with the added ability to reduce speed in smaller increments from the low medium low medium high and high settings. It uses a resistor to generate voltage drop and thus reduce the speed of a dc motor like the pc fan.

This voltage drop will be subtracted from the overall voltage on the fan and therefore the voltage across the fan will be reduced. However the motor will draw more current when starting up and as the load increases causing higher voltage drop and reducing speed even more. Among all circuits i have make this is the simplest one. In our psc example we would likely have had to slow the fan speed by 7 15 to give us the ability to get much closer to our target of 350 cfm ton.

The resistor will cause a voltage drop across its leads.