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, ...

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 ...

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 ...

Over the years, control relays of various types have been used by the hundreds — even thousands — to control nearly every function in commercial and industrial processes. Today, many of those ...

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 ...

My July 3 column covered the theory and operation of potential relays. This article covers potential relay ratings and specifications along with systematic troubleshooting. Here is an example of a ...

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 ...

If used correctly, a reed relay is a superbly reliable device. The switch contacts are hermetically sealed, so they don’t suffer from oxidization or contamination in the same way as an open ...

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 ...

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 ...