Ethcircuits.com is a portal to free Basic Electronic Circuits /engineering projects . All are carefully cross-referenced into a wide range of categories. These categories include amplifiers, power supplies, solar, hobby circuits, etc…. This site includes a collection of circuits designed by JATINDER KHATTER (founder of the website). This site is a vital resource for engineers, hobbyists, students, inventors & consultants.
Auto Cut-Off Battery Charger
This battery charger circuit provides the Automatic cut off the facility when the battery gets fully charged. You can use this circuit with any battery from 3.7 volt to 12 volt
Electronic Password Door Lock
This is a key code lock switch circuit, type of electronic circuit. To replace a conventional normal key switch, without inserts keys. But you can press the number code instead of unlocking keys.