Discover how to build a simple wireless power transfer system at home using readily available components like enameled copper wire, an LED, a 2N2222A transistor, and a 9V battery. This step-by-step ...

The project described in this article is a ready-made item from a $2.00 shop! And it is made in China! It is a wireless doorbell with a cost of about $10.00. It is so cheap, you could not build it ...

This wireless headphones transmitter assures a quality reception over 2 meters. The oscillator frequency is between 1750KHz and 3500KHz and for antenna we use a ferrite bar. IC1 amplifies the audio ...

With this circuit, a single transmitter and simple set of user pushbuttons can initiate one of four different outputs, two at each of two remote receivers with very different applications. The ...