Most speed control is accomplished by using a mechanical tachometer attached to a motor shaft to control electronics to maintain a set motor speed.
However a spinning motor is also a tachometer if the power is momentarily disconnected and the back EMF ( Electro-Magnetic-Force ) voltage measurement is used to control the power to the motor with a group of op-amps.
Linear Technology has an IC that can do this for you.
Comments
Best Answer 8 years ago
Use the back EMF voltage to regulate your speed control power
transistor.
A
Answer 8 years ago
What do i need to do that ?
Answer 8 years ago
Most speed control is accomplished by using a mechanical tachometer attached to a
motor shaft to control electronics to maintain a set motor speed.
However a spinning motor is also a tachometer if the power is momentarily disconnected
and the back EMF ( Electro-Magnetic-Force ) voltage measurement is used to control
the power to the motor with a group of op-amps.
Linear Technology has an IC that can do this for you.
A
8 years ago
This has be covered before several tims - resistors waste energy in heat and the motor will be very poor at regulating it's speed.
You need to control the voltage in a dynamic way.
For the rest much depends on the motor you wan to control.
8 years ago
Don't. Its a very bad way to control them.
Steve