Engineers are created in labs. Hence it is essential to keep the lab equipment current and close to the real world to create engineers...

One way to check whether anybody is at home is to ring the doorbell. Burglars too use this very technique. The circuit described here...

Here is a simple circuit that can produce the effect of candle light in a normal electric bulb. A candle light, as we all...

Today telephone has become an integral part of our lives. It is the most widely used communication device in the world. Owing to its...

Simple loop burglar alarms sound whenever the loop breaks. What if a clever thief comes to know of the working of this alarm? He...

Here is a simple circuit that starts playing the car horn whenever your car is in reverse gear. The circuit (refer Fig. 1) employs...

Here is an inexpensive circuit for a stereo amplifier to drive a low-impedance headphone set. The circuit uses a few cheap transistors (BC547 and...

Whiskers for robots are simple switch-type sensors that work like an animal’s whiskers detecting nearby objects in the environment. When disturbed, the sensor sends...

A logic probe is a handheld pen-like probe used for analysing and troubleshooting the logical states '0' or '1' of a digital circuit. While...

Here is a simple but inexpensive inverter for using a small soldering iron (25W, 35W, etc) in the absence of mains supply. It uses...