Relays usually are driven using optocouplers, which offer isolation between analog and digital grounds to ensure that switching currents in the relay coils do not affect the noise margin of the ...

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, ...

Among semiconductors, the muting transistor and its audio application is perhaps the most obscure and poorly understood of all. There is extremely little information on this subject available on the ...

Fig. 1: Add this relay to prevent shorted transistors in the MW-1. Usually after a transmitter is discontinued, any hope of upgrades or improvements fades. Some enterprising engineers can’t help but ...

How many remote controls do you have in your home? Don’t you wish all these things were better integrated somehow, or that you could add remote control functionality to a random device? It’s a common ...

Electronic relays have evolved a lot since their introduction in the early '30s, but their basic purpose hasn't changed. Transistors and integrated circuits have replaced vacuum tubes and the term ...

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 ...

I recently installed a new stereo head-unit in my car. One of the challenges with installing this head-unit was that a certain wire from the harness needed to be grounded, but only after the radio had ...

Last week I explained how to use a motion sensor to trigger an event with an Arduino. The event we triggered was a simple blinking of an LED. You can do a lot with a bunch of LEDs if you use your ...