A digital signal has non-continuous and discrete value, with finite resolution in time and magnitude. Digital signal always has two states either completely on (high) or completely off (low) and magnitude of amplitude will always remain stable. A simple digital signal is represented as a square wave as shown in the following diagram:
Figure 8.4
Due to the shortcomings of analog signal in control application, we use digital signal to control the same analog circuits because of the stable and discrete nature of digital signal. And here PWM comes into the picture.
PWM is a technique of generating analog signals using a digital ...
