Pulse width modulation also known as pulse time or pulse duration modulation reduces the average power delivered to a load by chopping electrical signals into discrete parts.
The average voltage and current delivered to the load is controlled by ON and OFF switching at a particular frequency, mostly at a fast rate.
The longer the switch is in the ON position relative to OFF position, the higher the total power supplied to the load.
The literal meaning of pulse width modulation is varying the width of pulse. PWM is used for varying analog signals from digital signals.
Advantage of using pulse width modulation in automobiles
1. In the automotive world, there is emphasis on efficiency and fuel economy. Manufacturers are improving every component to get better efficiency, less fuel consumption and less power consumption. PWM is used to minimize power consumption since the power to the load is not constantly ON. The switching frequency also known as duty cycle has to be high enough in order not to affect the load.