USB OTG Power Guard
As you may well know, you can borrow USB standard 5 volt dc supply from any smartphone equipped with USB on-the-go (USB OTG) port. USB OTG is a hardware (and software) standard that allows you […]
Universal 2S Li-Ion/LiPo Charger Module
This is a simple and 100% safe universal linear charger module for 2S Lithium-Ion (Li-Ion) and Lithium-Polymer (LiPo) batteries with the recommended constant-current/constant-voltage (CC/CV) charging algorithm. Initially charging takes place in the current mode and […]
Little Rescue Light
During an unexpected blackout in particular, a simple light source can be a handy aid. With only two transistors, one photo resistor, and a few other components you can build an automatic emergency light. Here’s […]
Infrared (IR) Adapter for Smartphone – Part 1/2
Nowadays you can use your smartphone as an infrared remote controller handset to control compatible home appliances, a music system for example. Since most of the smartphones available today do not have an infrared sender, […]
Simple Wireless Door Bell
Here’s an interesting circuit of a wireless door bell/buzzer for electronics students and hobbyists. The circuit is a short-range radio-frequency (RF) tone generator realized with the help of a cheap 433MHz RF transmitter & receiver […]
Tiny Tone Decoder Module
I’d made a number of tone decoder projects with the unique NE567 PLL tone decoder chip in 1990s, and most were published in Elektor Electronics (UK), Silicon Chip (AU) and Electronics For You (IN) magazines. […]
Portable Snake Repeller
Afraid of snakes? Don’t worry, here is a portable electronic snake repeller solution to keep all poisonous snakes out of your surroundings. All you need is to simply put the device on the bare floor/soil […]
Little Melody Maker
Here is a simple do it yourself project of a little melody maker useful for all those hobbyists interested in making electronic toys or fancy gizmos for their kids. For extreme simplicity and flexibility, the […]
A Cute Night Lamp
Once again, here is the circuit diagram of a little night lamp wired around the evergreen 555 tiny timer chip. The circuit, designed to run on a standard 6F22 9V battery, can be used as […]
USB Power Bank Adapter
USB Power Bank – popularly known as mobile phone emergency charger – is an ideal solution for powering small microcontroller based hobby projects. Even the cheapest power bank in the market has so many useful […]