I was wondering how a remote control for a fan changes the speeds of the fan. Does the circuitry in the remote control change the speeds or is there a capacitor in the fan that changes the speeds. If it is a capacitor, I can't figure out how the receiver would be able to make the capacitor work because there is only one feed wire to the motor.
Thanks, Terry

The transmitter sends a coded string of signals, when you push high, it transmits to receiver, it see "High" signal, and makes the connections that the Normal fan speed and direction switches do. There is 1 wire powering the fan but actually several are used to control speed/direction. Capacitor value helps control speed. Different value will get different speed. Wouldn't advise changing. Fan people been doing this for years.
The receiver could have a microprocessor to toggle through the speeds or something not obtainable with common switch, holding down continiously on remote can brighten. Whereas a switch can not.

There are generally two types of fan speed regulation: capacitors, and different coil taps in the motor. The latter type will have a lot more wires going to the motor than the former.

Before I answer any more, are you talking about an add-on remote kit or a built in remote?

Frequently asked ceiling fan questions - Ceiling Fans N More
Ceiling fan remote controls - help and FAQ- Ceiling Fans N More
Ceiling fan remote controls - help and FAQ- Ceiling Fans N More