LED turn on by LDR when dark. LDR and resistor connect in voltage divider circuit. In bright light transistor base get low voltage so transistor stay OFF. When dark come LDR resistance goes down and base voltage goes up with transistor turn ON and LED light up. This Simple Darkness Detector Circuit is easy to […]
Sensors and Detectors
Motion Detector Circuit using IC 555
This easy Motion Detector Circuit uses IC 555 to find human from far. Circuit have two parts: Transmitter: IC 555 work like astable multivibrator and it make square wave signal. This signal goes out through IR sensor (infrared). Receiver: Phototransistor see IR beam. If someone moves and block the beam then phototransistor work and turn […]
Simple Non-Contact 220V AC Detector Circuit using IC 555
Playing with electric wire is risky especially if we do not know electronics. Wrong use of electricity can be dangerous. So better to be safe before touching wire and first check if some electricity with leakage voltage is still there. This article for Simple Non-Contact 220V AC Detector Circuit using IC 555 show how to […]
Broken Cable Detector Circuit using IC CD 4069
This post is for Broken Cable Detector Circuit using IC CD 4069. In this circuit there is no need to open wire to check. It work like metal finder but find AC current in wire but not in metal. It uses chip CD 4069 and this chip has small switches to turn ON light or […]
TV Remote Signal Jammer Circuit
555 IC is used in this TV Remote Signal Jammer Circuit. It makes fake IR signals same as remote so TV get confused. TV can not get the real remote signal. We can watch the show without anyone changing the channel. Parts used to complete this circuit are IR LED, ceramic capacitor, NPN transistor, potentiometer, […]
Simple Metal Detector Circuit using IC 555
This is Simple Metal Detector Circuit using IC 555 It uses IC 555 chip which works like small clock and makes signal to help find metal and magnet It is easy to build and good for beginners. Circuit Working: Parts List: Component Type Value Quantity Resistor (1/4 watt) 47k 1 Capacitors Electrolytic 10μF 25V 1 […]