While servicing an elevator at an older San Francisco high-rise hotel, an elevator technician accidentally created an electrical arc flash at the fused switch. This accident left him permanently ...

Last column, I wrote about various applications where fire alarm relays could be used to integrate a commercial fire alarm system with other electrical systems at a customer’s site to provide them ...

The control system of an elevator consists of a low voltage circuit, that supplies the motor brake and the relay coils. In this link you can see a basic circuit, designed for educational purpose. At ...

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.

When designing equipment with switching functions, most engineers find that switching high currents and high voltages is a major problem. A solid-state solution may be possible, but it’s complex and ...