[Teodor] writes in with a unique Tesla coil he designed and built. Unlike most Tesla coils, [Teodor]’s design is able to run with a fairly low input voltage because it doesn’t use a static spark gap ...

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 ...

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 ...

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, recently ...

What’s one to do with some nice little relays of questionable pinout, and prototyping board? How about a quietly clicky 4-bit counter using relay logic with tons of buttons? [Agatha Mallett] ...

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 ...

One of my favorite activities is discovering the inner secrets of electronics systems as I am always looking for interesting design ideas. That way, I can take those design tricks a step further, ...

I know, I know—discussing the subject of a relay-based sequence switch in the age of omnipresent microprocessors seems to be a waste of time. After all, relays have been in use for many years. Is it ...