PCBX

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 […]

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 […]

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 […]

Temperature Coefficient of Resistance

Temperature coefficient of resistance, this is the factor that temperature does affect the value of resistance in a resistor or a conducting wire. All the resistors value of resistance is specified at specific temperature and […]