When depicted in drawings, relay contacts are shown de-energized — that is, with the power off the coil. Types of contact symbols are shown in Fig. 1. Also known as ice-cube relays, plug-in relays are ...

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 ...