Ldr Security Alarm Circuit Diagram. Let s get started add tip ask question comment download. This is a project of smiple laser security alarm circuit.
Part s list 1 bc547 transistor 1 220 ohm resistor 1 330 ohm resistor 1 bright 5mm led 1 ldr light dependent resistor 1 6v power supply 3 7 v also will w. When there is no light fall on the ldr the transistor driving the speaker is not turned on because its resistance is high. This is a light alarm circuit.
This circuit uses light dependent resistor ldr.
Easy laser light security system circuit at home. When the ldr receives light its resistance decreases and the collector of the second transistor falls. This is a light alarm circuit. Let s get started add tip ask question comment download.
