Relays and contactors use a variety of technologies to switch signals and power connections. Many devices called relays use similar techniques and topologies, but the terminology can be confusing.

This chapter covers representative general-purpose relays used in the control circuits of most industrial, commercial, and consumer products. Relay names and terminology are in accordance with ...

As automation expands, mechanical functions are relying more and more on electronic control. Solenoids provide an electromechanical interface for many of these applications. In addition, many ...

The reed relay was invented in 1936 by Bell Telephone Laboratories. Since that time, it has gradually evolved from very large, relatively crude parts to the small, ultra-reliable parts we have today.