[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 ...

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Among his numerous innovations, Nikola Tesla dreamed of creating a way to supply power to the ...

This Design Idea shows how to use a 63¢ (Q=1) microprocessor reset voltage detector IC in a relay coil drive circuit to greatly reduce the coil’s hold-in current. When asked to estimate the coil ...

An electrical relay is a type of heavy-duty, remote-control switch able to handle high-current accessories, yet capable of being actuated by substantially less current. Relays install between the ...

The fan center’s purpose is to control when the indoor fan turns on. Before the integrated gas control board, the indoor fan on gas and oil furnaces would either turn on at the same times as the heat ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. I’ve always thought it would be funny to build scale-size ...

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 ...

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, ...

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 ...