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 ...

In this article, I'll show you how to make a simple touch-triggered switch. This is very useful for various electronic projects, from a simple bedside light to a flat panel touch keyboard. The circuit ...

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 ...

Inside there's a coil of wire wrapped around an iron core. When a current flows through this control wire, it creates a ...

The two types of standard transistors are PNP and NPN which differs in circuit symbols. The layers of semiconductor material used to make the transistor are denoted by the letters. To keep a straight ...

A teacher I know is stuck, with only npn transistors in the supply cupboard and the need to create a reversible motor drive for an Arduino project. Reversing ‘bridges’ have four switches (relay ...

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 ...

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 ...

The transistor is probably the most important invention in electronic engineering and the basis for nearly all integrated circuits (ICs). The transistor is a three-terminal electronic device that can ...

[Dr. Cockroach]’s goal was to build a four-bit computer out of recycled and repurposed junk. The resulting computer, called IO, consists of a single 555, around 230 PNP and NPN transistors, 230 diodes ...