Power Control 425
operations. A typical application would be as follows: (1) a “start” push-
button is pressed, (2) a timing relay is activated, (3) after a 5-second time
delay, a motor is turned on.ELECTRONIC POWER CONTROL
Solid-state power controllers are capable of replacing electromag-
netic circuit breakers and relays used for electrical power control. The in-
troduction of computerized control for industrial equipment has brought
about a new technology of machine control. Many industrial machines,
such as automated manufacturing and robotic equipment, are now con-
trolled by computerized circuits. An understanding of the basic principles
of electrical control is, however, still very important for technicians.