The example circuit used in various situations, such as control lamps or other device that needs to be turned off when the daylight. It is based on LDR (Light Dependent Resistor) is a special resistor that varies its electrical resistance according to the amount of light falling on its surface.
The circuit shown is easy to assemble and uses a light sensor ldr as the 10K potentiometer regulates the working point for your application. When light focuses on the LDR, the transistor turns on the relay that can handle various types of loads. As the LDR does not have a rapid response, rapid variations of light undetected, as lightning.
The LED serves to indicate the state of the circuit active or inactive and in many cases can be omitted by placing a jumper in place. To feed the circuit uses a 12 volts / 500mA power supply .
PCB for module light sensor
|Resistor’s 1/4 watts 5%|
|R1||1.8KOhms – Black, Gray, Red, Gold|
|R2||680 Ohms – Blue, Gray, Brown, Gold|
|P1||10k – Trimpot|
|Q1||BC548 or equivalent – NPN Transistor|
|D1||1N4004 or equivalent – Diode|
|LED||LED 5MM – Led.|
|VCC||AK500/2 Power supply Connector|
|CN||AK300/3 Load Connector|
|K1||Relay Onrom G5LE or equivalent|
|PCB, box, wires etc.|