12V Load-Acid Battery Monitor

12V Lead-Acid Battery Monitor

…This circuit, with the components shown, uses less than 10mA. You can modify this circuit to your own needs by making small modifications. The above circuit diagram is set for

Mini UPS circuit

Mini UPS Project

…time. A common step-down transformer delivers 12V of AC, that is rectified by diodes D1 and D2. Capacitor C1 features ripple-free DC to charge the battery and to the remaining…

Cheap Motorcycle Alarm

Cheap Motorcycle Alarm

…the motorcycle from pillaging. Tilt switch S3 prevents attempt to move the vehicle without starting it. Glass- and metal-bodied versions of the switch offer bounce-free switching and quick break action…

Short Wave AM Transmitter

25 Metres Range, Short Wave AM Transmitter

Here the short wave AM Transmitter circuit design diagram. The circuit is quite simple and easy to build since it applies only a few electronic components. The primary feature of…

Desktop Power Supply Circuit Electronic

1 – 9V Variable Desktop Power Supply

…supply box shown below: Then open up the case of the desktop computer and hook up the input line of is circuit to a free available (hanging) four-pin drive power…

Laptop protector circuit

Notebook Anti Theft Protector

…circuit is operated by a 12V miniature battery applied in remote control devices. IC TLO71 (IC1) is utilized as a voltage comparator with a potential divider composed of R2 and…

DIY Electronic Cardlock Security System

…to insert the card wrongly, it will not go completely inside the mechanism and the system will not be enabled. When card for any appliance (say appliance 1) is completely…

Train Horn Circuit with 2 Tones

Two Tone Train Horn based NE556 Dual Timer

…or a low tone. The 556 contains two seperate 555 timers so feel free to use the 555’s. If you don’t want to fiddle with the reed relay that is…