Regulate Me

We all have used fans and wondered how a regulator works. I’ll explain that, but let’s take it a step further. Today’s question:

Does the Highest Speed of a 5-speed Fan Differ From a 7-speed Fan?

Let me clarify a bit, 5-speed means the regulator has six settings (0, 1, 2, 3, 4, and 5). Before this, let’s first understand how a regulator works.

Above is the circuit diagram of a fan regulator. How it functions you ask? It’s simple. The regulator is just a bunch of resistors in series with the fan motor. The lower the value of fan speed, the higher is the amount of resistance across the circuit.
The increase in resistance leads to the decrease in current flowing across the fan motor (as the voltage is always constant at about 220 V). Thus, the speed of the fan decreases at lower fan speed values of the regulator.

Now, as you may have guessed, both in a 5-speed regulator and a 7-speed regulator, the end (or the highest speed, i.e., 5 or 7) will have zero resistance. If both the fans run with the same voltage difference across the fan motor and no other difference (except the 5 and 7 point regulators), they will both rotate at the same speed. Don’t be fooled by that one braggy friend who says their fan rotates faster.

Don’t worry braggy friend, the 7 point regulator provides a finer control of the fan speed and may be considered superior in that way.