Water Pump Controller

Here is a simple circuit for controlling water level in an overhead tank. The main components of this pump controller are a step-down transformer, a 24V AC double-changeover relay, two floats...

BIPOLAR TRANSISTOR TESTER

This tester is primarily meant to test bipolar transistors. It can indicate the type of the transistor as well as identify its base, collector and emitter pins. The circuit is very...

Digital Soil Moisture Tester

Here is a simple and compact digital soil moisture tester to check whether the soil is dry or wet. It can also be used to check the dryness or wetness of...

Over-Heating Indicator for Water Pipe

The hot water pipe from the water geyser of your bathroom may burst if it gets overheated and is left unattended. This circuit monitors the temperature of the water pipe. If...

Simple Key-Hole Lighting Device

When opening the door of your room in the dark, you may have to spend a few minutes searching for the key-hole. Here is the circuit of a lighting device that...

Triple-Mode Tone Generator

Here is a simple circuit that generates three different tones. You can use it as a call bell, burglar alarm or any other security alarm.Fig. 1 shows the circuit of the...

Night Vision Enhancer

Here is a simple green LED flashlight built around 555 timer IC (IC1) and powered from a 3V battery pack. Green LED based flashlights are widely used by hunters and others in...

Halogen lamp Saver For Bikes

Halogen lamps are prone to burn-out owing to their low cold current. The rapid heating inside the lamp melts the thin filament and cuts the lamp life short. The circuit described...

Ball Speed Checker

This circuit measures the speed of a cricket ball based on the time taken by the ball to travel the distance from the bowling crease to the batting crease. As shown in...

MOBILE ELECTRONIC WORKBENCH

Typically, implementing and testing even a small circuit requires an elaborate setup that includes breadboards, a dual DC power supply, hookup wires, ICs and resistors of different values. This setup can...