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 ...

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 ...

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, ...

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 ...

Astute commenter of this parish zeitghost has drawn my attention to a rather neat application note on relay contacts, on the website of TE Connectivity. The wisdom includes: “Transformers can present ...

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 ...

Have you ever needed to power a 12-volt relay in a circuit but only had 6 or 9 volts available? This simple circuit will solve that problem. It allows 12-volt relays to be operated from 6 or 9 volts, ...

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 ...