He hooks up the SN754410 to two motors, giving him speed and direction control for both based on the duty cycle of a PWM signal entering the chip for less than $2.50.

Brushless motors are ubiquitous in RC applications and robotics, but are usually driven with low-cost motor controllers that have to be controlled with RC-style PWM signals and don’t allow fo… ...

The back EMF, along with the RL circuit in a brushed DC motor, brings non-linearity to the PWM control and the PWM frequency and PWM duty cycle become significant for getting the best output power.