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...

Standards and tests are essential to evaluate the quality and longevity of LEDs and luminaires. So test and measurement solutions have to keep pace...

The erratic behaviour of frequency-hopped signals makes them difficult to capture, verify and measure. Hence more effective tools and processes are required to design...

Though the reliability of brain scanning for lie detection is still under question, these tests are fast becoming popular with the crime investigating teams....

Here’s the circuit of a multi-switch input musical doorbell (shown in Fig.1). The circuit is built around the popular and less expensive quad D-latch...

This circuit (Fig. 1), used in conjunction with a thin piezoelectric plate,senses the vibration generated on knocking a surface (such as a door or...