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, ...

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 ...

A simple and convenient way to interface 2 relays for switching application in your project. This relay driver boosts the input impedance with a regular BC547 NPN transistor (or equivalent). Very ...

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 ...

For switching high-powered loads from a microcontroller, or for switching AC loads in general, most of us will reach into the ...

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 ...

In electronic and industrial automation systems, relay modules play a crucial role by allowing low-power control signals to switch high-power devices. Selecting between a 5V relay module and a 12V ...

A very simple but highly efficient combination lock circuit is shown in the figure. Any type of on/off switches can be used, varying from commercially available inexpensive types to more sophisticated ...