As an electric motor’s rotor turns in close proximity to the motor windings, a bucking voltage or back electromotive force (EMF) is generated. The back EMF (BEMF) generated across the start winding is ...

Potential relays are commonly found on many smaller, single-phase, capacitor-start, capacitor-run motors in the HVACR industry. Their function is to assist in starting the electric motor. Potential ...

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.

Programmable logic controllers (PLCs) and computer-based controllers are great for handling logic and data-collection tasks for industrial controls. But when it comes to driving motors, heaters, ...

Achieve max electric fuel pump output and safety using a relay plus an oil pressure safety switch. Achieving maximum output and safety with a custom-wired electric fuel pump requires a properly ...

Even the best relays can fail at some point, but what causes them to fail? Conventional wisdom lays the blame on worn-out contacts. And there is some truth to that view. Every electromechanical relay ...

Relays continue to be useful and popular, but in low-power, battery operated applications they tend to be power wasters. The following relay economy circuits reduce coil power significantly by simply ...

No matter what the application is, when a definite-purpose solution is required, time delay relays (TDRs) can provide simple, reliable, and economical control. Adjusting the delay time is often as ...

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 ...

Relays are clunky, switch slowly, have contact bounce, and make noise, both acoustically and electromagnetically, so why are they still used? Relays are clunky, switch slowly, have contact bounce, and ...

Electromechanical relays can be manufactured with high-frequency RF characteristics that allow them to pass and switch signals in the 7-GHz range and beyond with the proper packaging. Two key RF ...