Some relays will become warm if they remain energized for some time. The circuit shown here will actuate the relay as before but then reduce the ‘hold’ current through the relay coil current by about ...

Many varieties of ON/OFF control circuits use some form of flip-flop that responds to a pushbutton switch or other control input. These all have volatile memory and default to an OFF condition if ...

A transformer switching onto a line can sometimes cause a circuit breaker to trip or a fuse to blow. This phenomenon occurs even if the transformer presents no load, such as when the secondary is open ...

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.

Relays are electromechanical devices that use a magnetic solenoid to actual a switch. When current is passed through the solenoid coil, it produces a magnetic field. The magnetic field is strengthened ...

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 ...

A common theme in modern consumer electronics is having a power button that can be tapped to turn the device on, but needs to be held down when it’s time to shut it off. [R. Jayapal] had noticed a ...