Introduction
Consider some problems:
● A pump in a domestic or industrial heating system must be switched on and off at preset times.
● A series of high-intensity lights around the perimeter of a factory complex are to be activated in the event of a security incident.
● An electrical heater in a brewery must be used to maintain a precise temperature.
● The motor in a washing machine must go through a pre-programmed series of movements.
In these – and many other applications – we need safely and reliably to control comparatively high-level AC supplies. In this chapter we will consider two popular approaches to this problem
● EMR DRIVER [page 149]
● SSR DRIVER ( AC ) [page 156]