Home >> Hobbies >> Other Hobbies

How to Control a 3 Pin Brushless DC Motor

A 3 pin brushless motor requires three different voltages in order to operate. A different waveform is applied to each pin, similar to a three-phase voltage being applied to an AC motor. These motors are commonly used in laser printers. The speed and power of these motors can be adjusted by changing the inputs on the three input pins. These pins are typically controlled by an electronic circuit which can produce changing waveforms at each motor input pin.

Things You'll Need

12-volt battery
Motor controller signal generator

Instructions

- 1
  Connect the battery to the positive and negative terminals of the motor controller. Next connect the output terminals of the controller to the three pins of the motor. The controller is a signal generator which generates a square wave signal and transmits this signal to the motor pins.
- 2
  Adjust the generator so that the square wave has more off time than on time. This sends less power to the motor so it turns slower with less power. A square wave is characterized by the amount of time the output receives full output voltage and the amount of time the output receives zero voltage.
- 3
  Increase the pulse width so that the pulse "on" time equals the pulse "off" time. The motor will operate at one half its full power. If the "on" time is increased with no "off" time, then the motor will run at full power.

Other Hobbies