Homework 2 Solution
motors.
1. Draw the motor current and the motor voltage characteristic during the
operation with a constant PWM signal of 50% duty cycle.
2. Recommend the suitable range of frequency for this PWM applied in
mictrocontrollers. Analyze the advantages and disadvantages of PWM
systems.
Solution:
1. Draw the PWM signal of 50% duty cycle for the motor current and voltage:
UMotor
50% On & 50% Off
UMotorMax
t
IMotor
2. Recommend: t
Recommend the suitable range of PWM frequency: Since the human hearing
range is from 20 Hz (cycles per second) to 20 kHz (20,000 Hz), the PWM for