Traffic Controller
This simple traffic controller can be used to teach children rudiments of traffic rules.
The circuit (shown in Fig. 1) uses readily available components. It...
Hot-Water-Ready Alarm
Electric kettles turn off automatically when water has boiled. What if the boiler beeps to alert you when your water has boiled? The tripping...
Peak Hour Timer
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....
DIY Touch Alarm
This is a new type of touch alarm that uses an RF oscillator at its input. One special feature of this touch alarm is...
DIY Electronic Heart
With this electronic heart glowing on and off, you are sure to steal the heart of that special someone. The circuit uses an NE555...
CAR ANTI-THEFT GUARD
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...
GLOW PLUG CONTROLLER
In diesel engines, the air in the cylinders is not hot enough to ignite the fuel under cold conditions. Therefore each cylinder of these...
Cordless Multi-Door Alarm
Thwart the attempt of burglary by detecting intrusion with this alarm circuit. Each door is protected by a separate circuit built around an independent...
MOBILE BUG
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...
Line-Powered Two-Tone Ringer
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...