For procedures, see your electrical laboratory manual.

Title: The Simple Resistive Fan Regulator


Aim

To observe the performance and trace the circuit of a simple resistive fan regulator. Then to make simple resistance measurements to verify its performance.

Apparatus

1. One Resistive fan generator
2. One 2A Variac
3. One 440 Rheostat
4. One Bridge Megger
5. One Crumption 1A moving from an ammeter

Theory

A fan regulator is a crucial component that serves to increase or decrease the speed of your fan according to your needs.

Any electrical conductor allows current to pass through it. The conductor, however, offers a certain amount of resistance to the passage of current. The resistance depends upon the material of the conductor.

The regulator has spools of wire with different amounts of resistance. When you set the knob at a particular position, you include a certain resistance in series with the fan. A series connection implies the resistance is in line with the fan. This reduces the voltage drop across the fan and its speed to your desired level. The greater the resistance, the higher is the voltage drop across it and that lowers the speed of the fan.

Due to the advancement in power electronics technology, the alternative design of the fan regulator (voltage regulator) can be easily implemented to reduce the energy losses that are caused by conventional voltage regulators.

This type of voltage regulator is an energy-saving device that uses TRIAC, DIAC, and potentiometric resistance. This method provides the step-less control of the fan speed by deriving the required amount of power from the mains supply at a given instant.