An LDR changes its resistance when light falls on it and alight detector circuit uses this property in a Wheatstone bridge. One side of the bridge contains the LDR and a fixed resistor connected in series, while the other side contains a potentiometer and another fixed resistor connected in series. Furthermore, the circuit applies a […]
LDR Circuits
Simple Door Keyhole Light Circuit
When ON, small device like Simple Door Keyhole Light Circuit gives light to keyhole, as it helps to put key in hole when light is low. Also, it uses light sensor and circuit to check light level, hence, to switch it by light we used transistor and LDR. Circuit Working: Parts List: Components Values Quantity […]
Simple Electronic Candle Circuit using LDR
This article for Simple Electronic Candle Circuit using LDR is fun and easy project to make fake candle with LED, as it uses LDR to make LED flicker like real flame and turns ON when its dark; also LDR controls the LED. Furthermore, in bright light the LDR has high resistance so LED stays OFF […]
Simple Flasher Circuit using LED and LDR
This simple flasher circuit uses an LED and an LDR to create the flashing effect; as the light level changes, the LDR changes its resistance, which controls the LEDs blinking. Hence, there is no need for big chips or transistors but still the LED blink happens, also it uses simple parts like resistor, capacitor and […]
Simple Light Dependent Screamer Circuit
Fun small and Simple Light Dependent Screamer Circuit make sound change with light; it uses LDR like a special resistor which changes with light. Furthermore, as the light intensity increases, the sound becomes louder or higher in pitch, therefore, we call this circuit a Light-Dependent Screamer. Circuit Working: Parts List: Components Values Quantity Resistor 1k […]
Solar Tracker Circuit
Think like small helper robot for our solar panels. Solar Tracker Circuit works like smart assistant which helps solar panels to always look at sun, as sun moving in sky the whole day. Also, this circuit have sensor it sees where sun goes and change panel direction by itself. When panel always faces the sun […]




