system
Given the following post, respond as if you're commenting on Reddit:
human
[Electrical Engineering] If electric fan knobs are made to resist a set amount of electricity, then is the amount of elecricity consumed in the fan equal regardless of the amount of resistance in the knob?

In advance, I apologize for the horribly butchered question. I wasn't quite listening during workshop class.
gpt
Firstly, fans no longer use resistors, or rheostats, to control their speed. They either use switches that rewire the coils, or dimmer controls of various complexity that use, in one way or another, triacs as switches to control the amount of power that reaches the fan. These control methods are highly efficient, so the power used by the fan goes down by a lot as you slow it down.

Even in the old rheostatic controls, they'd use less power as you turned them down. As you increased the resistance, you'd have less current flow, and as the voltage across the circuit remained constant as the current decreased, (P=VI), the power dissipated by the whole circuit would decrease. But the overall efficiency drops, as, for instance, if you used the resistor to halve the current, The whole thing would use half the power. But the fan would only see half the voltage, and half the current, so would run at 1/4 of the power. The same amount of power would be dissipated by the resistor. This is why we don't use them any more!