This Design Idea shows how to use a 63¢ (Q=1) microprocessor reset voltage detector IC in a relay coil drive circuit to greatly reduce the coil’s hold-in current. When asked to estimate the coil ...

An RC circuit in series with the coil allows full-current turn-on for reliable relay operation, then reduces the current to save power. Fellow engineer Sanjay R. Chendvankar of Mumbai, India, recently ...

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 solenoids are available with many different voltage ratings. Most factory- and process-automation equipment operates from 24-V supplies. However, customers may have control signals for a ...

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.