FM Adaptor for Car Stereo

If your car has an FM radio with stereo output but no inbuilt cassette player, this circuit will come handy for listening to your favourite collection of music from your personal...

DC-TO-DC Converter

Here’s a low-cost circuit to convert 6V DC into 12V DC. It uses no transformer and is easy to construct with few components. The circuit is built around IC 555, which generates...
MOSFET based preamplifier

MOSFET based Preamplifier for FM Radio DXing

FM transmissions can be received within a range of 40 km. If you are in fringe areas, you may get a very weak signal. FM DXing refers to hearing distant stations...

Non-Contact Power Monitor

Here is a simple non-contact AC power monitor for home appliances and laboratory equipment that should remain continuously switched-on. A fusefailure or power breakdown in the equipment going unnoticed may cause...
infrared interruption counter

Infrared Interruption Counter

Most optical interruption counters make use of a light bulb with light-dependent resistor (LDR) or ordinary phototransistor as the sensor. The interruption counter work satisfactorily in darkness only and cannot be...

Little Door Guard

If some intruder tries to open the door of your house, this circuit sounds an alarm to alert you against the attempted intrusion. The circuit (Fig. 1) uses readily available, low-cost components....

Power Failure and Resumption Alarm

This circuit gives audio-visual indication of the failure and resumption of mains power. The circuit is built around dual timer IC LM556. When mains is present the bicolour LED glows in...

Solar Bug

Hide this solar-powered circuit suitably and see the reaction of your friends to the chirpy sound produced by it every few minutes. In all probability, it will coax them to find...

Accurate Foot-Switch

Certain industrial controls require accurate switching operations. For example, in case of a foot-switch for precise drilling work, even a small error in switching may cause considerable loss. This low-cost but...

Power-on Reminder with LED Lamp

Many a times equipment at workstations remain switched on unnoticed. In this situation, these may get damaged due to overheating. Here is an add-on device for the workbench power supply that...