By T.K. Hareendran

International Electronic Design Freelancer • Technical Author • Hardware βeta Tester • Product Reviewer
Articles Written 466

Loafer’s LED Wick

May it be a surprising title – Loafer’s LED Wick! Let it be, the article is nothing but the design idea of a little LED light based on Joule-Thief concept. It’s true that by a […]

Simple Thermostat for Electric Geyser

Here is a simple yet highly reliable thermal control circuit which can be used with almost all electric geysers. The Arduino microcontroller based circuit switches an electromagnetic relay on or off according to the temperature […]

Breathing New Life into BLDC Motors

It’s damn sure, there’s plenty of old optical and magnetic disc drives (CD/DVD/HDD) in every electronics/hardware hobbyist’s junk box. Sadly it’s known to few people that such disc drives are rich and cheap sources of […]

Optical Smoke Alarm

Optical smoke alarms, also known as photo-electric smoke alarms, are particularly useful in bedrooms, lounges, hallways, and in other areas where we can otherwise expect false alarms from the common ionization smoke alarms. An optical […]

Digital Pulse Counter

Recently I came to understand the true demand for a multi-purpose digital pulse counter. So I designed an east-to-build digital pulse counter circuit based on some generally available cheap electronic components. The quick microcontroller based […]

Travel Door Sentry

Here’s a travel door sentry to safeguard your hotel room with a simple door sensor that will trip a warning alarm if anyone unlocks the door and intrudes. The battery-operated portable security device is very […]

Nifty NiMH Battery Charger

And now another interesting little project. After seeing numerous online projects I decided to build my own simple NiMH battery charger circuit using NiMH batteries because a bunch of GP2100 series NiMH cells are lying on […]