That’s because brushless DC motors require carefully timed signals used in a process called Electronic Speed Control (ESC). [Fileark] built and ESC using an Arduino and has a couple of posts ...

The circuit in the figure provides three levels of speed control for a dc motor, using a PC’s parallel port (LPT1). A C++ program performs the control functions by allowing the signals from the ...

DC motor speed controller BMD-20DIN ver.2 Smart Motor Devices Smart Motor Devices Smart Motor Devices has improved the controller BMD-20DIN by expanding ways to control speed of DC motor – new ...

You can also use a single thyristor, a full-wave unsmoothed supply, and a pot to control the speed. The back-EMF from the motor switches the thyristor off when the voltage drops, the pot setting ...

The motor-speed-control circuit in the figure shows an SG3524 pulse-width-modulation (PWM) IC, U2, ... Low-Cost Circuit Controls PM DC-Motor Speed. Sept. 29, 2003.