Reduce Fan Speed Using Resistor

So we can use a 2 5kω resistor as our r2 resistor with the r1 resistor being 10kω.

Reduce fan speed using resistor.

The speed of a permanent magnet dc motor is primarily determined by voltage. If the motor draws constant current then the resistor will drop a constant voltage and the motor will run at a fixed lower speed. If we use a 10kω as our r1 resistor plugging in the values we get r2 v r1 vin v 1v 10kω 5v 1v 2 5kω. You could also use a simple 1n4001 diode in series with the positive wire to drop 7 of a volt for each diode you use doing it this way still lets you draw exactly the same amount of current about 500ma and it purely drops voltage and nothing else whereas a resistor in line will have an effect on current also.

This highlights one potential pitfall of this method you can t safely use 1 4w resistors for this unless you make up the target resistance using several smaller resistors of equal value in series. The resistor will dissipate 0 55 50 25w. Say if you have the same circuit above with 5v but only want 1v. As for the resistor wattage here comes the good news.

The problem with using a series resistor is that its voltage drop is proportional to current. The more the resistors that takes part the more the voltage drop generated thus the less the speed of the motor. You can use a selector with more positions for more speed adjustments. I m not sure how slow the fan will go though.

High protein breakfasts especially ones that include eggs nnbsp have been linked to weight loss reducing reduce fan speed with resistor belly fat in the process add eggs to salads stir frys and sautés or pair them with 100 whole grain toast and veggies for a hearty breakfast. So it s easy to see now how any voltage can be obtained with a resistor voltage divider circuit. Let s do one more example. 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.