Electrical appliances like refrigerators and air-conditioners consume heavy current if the line voltage drops during the peak hours between 6 pm and 9 pm....

This is a new type of touch alarm that uses an RF oscillator at its input. One special feature of this touch alarm is...

This circuit will turn the heater ‘on’ when the temperature of water falls below the lower limit set by you and turn it ‘off’...

With this electronic heart glowing on and off, you are sure to steal the heart of that special someone. The circuit uses an NE555...

Here is an easy-to-build car anti-theft guard. The circuit, shown in Fig. 1, is simple and easy to understand. When key-operated switch S2 of...

In diesel engines, the air in the cylinders is not hot enough to ignite the fuel under cold conditions. Therefore each cylinder of these...

Thwart the attempt of burglary by detecting intrusion with this alarm circuit. Each door is protected by a separate circuit built around an independent...

This handy, pocket-size mobile transmission detector (Mobile Bug) can sense the presence of an activated mobile phone from a distance of one and a-half...

Need often arises for having an extra telephone ringer in another room to alert you of an incoming call. A low-cost, 2-tone ringer IC...

Protect your valuable laptop against theft using this miniature alarm generator. Fixed inside the laptop case, it will sound a loud alarm when someone...