Which device connects power to motors and uses PWM to control motor speed?

• A. Motor controls
• B. Microcontroller
• C. Battery
• D. Sensors

Answer: (A)

PWM lets you vary motor speed by changing how long the power is on in each cycle. The device that actually wires power to the motor and uses that PWM signal to control how fast the motor spins is the motor controller (motor controls). It handles the high-current switching, often providing protection, direction control, and braking, while the control signal that sets the speed often comes from a separate microcontroller. A microcontroller can generate the PWM signal, but it usually can’t supply the large current the motor needs. A battery only provides power, without regulation or switching, and sensors don’t drive motors at all.