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 ...

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 ...

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 ...

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, ...

Hybrid relays combine a mechanical switch with a solid-state switch, and they are set up in parallel to control a single load.

This chapter covers representative general-purpose relays used in the control circuits of most industrial, commercial, and consumer products. This chapter covers representative general-purpose relays ...

Siemens Smart Infrastructure has launched a new series of coupling relays, with housing made from plastic that consists of 70 ...

Reed relays have evolved from their audio roots to handle GHz signals; MEMS technology may push them aside. This section ...

When you are used to working with semiconductor devices, the data sheets for relays may pose some problems. What do terms like ‘Operate Voltage’ and ‘Release Voltage’ mean, for example? When you are ...

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 ...

Many varieties of ON/OFF control circuits use some form of flip-flop that responds to a pushbutton switch or other control input. These all have volatile memory and default to an OFF condition if ...