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 […]

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 […]