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 bit of googling you can see an avalanche of the said Joule-Thief circuits, hope that fits but a moment here… [Read More]
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 sensed by a single chip temperature sensor LM35DZ. When the sensor detects a temperature lower than the pre-settled threshold level,… [Read More]
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 (otherwise costly) brushless direct current (BLDC) motors. Here’s a prefatory article to shed some light on the revival tricks of… [Read More]
Over Voltage Protector (OVP) Switch
In yesteryear I’d designed and developed an AC230V over voltage protector switch based on the popular PIC microcontroller PIC12F675 (shown below is the photo of that prototype). The electronic switch can be used to safeguard electrical appliances running on household AC230V mains supply from unexpected over voltage mishaps. Here I’m introducing another version of the… [Read More]
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 smoke alarm have a quick response to visibly smoldering fires, and the optical sensing technology makes it less prone to… [Read More]
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 design comprises of the following: Digispark Attiny85 Development Board (original/clone) TM1637 4-Digit Red LED Display (Catalex) Mini Reed Switch Module… [Read More]
How to Play with a Water Pressure Sensor?
Water Pressure Sensor is not a familiar everyday sensor for most electronics hobbyists and makers, so here’s an introductory tutorial on a popular water pressure sensor – the DFRobot Gravity: Analog Water Pressure Sensor. In this session, I’ll show you the basic sensor application and a simple demo on water pressure detection! DFRobot Gravity –… [Read More]
Resistor Color Code
Resistor color code indicates that a series of colored bands are painted on the resistor and most of the manufacturers identify their resistance value by means of a color code. There are various values of resistors available from some ohms to millions of ohms. It is not possible to have each and every value of… [Read More]
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 easy to use as it has a small leaf switch (two thin metal blades) that fit in the narrow gap… [Read More]
Electric Water Heater Thermostat Module
Let me introduce another simple do it yourself project, this time an electronics thermostat for residential electric water heaters. The circuit is designed for use in two-element water heaters in the upper position (upper thermostat), and is a good alternative to the time-tested “bi-metal” thermostats. A Typical residential water heater has two heating elements, the… [Read More]
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