Automatic Light controller 3

Automatic Light Activated Bulb Switch Controller

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Automatic ON OFF light switch circuit 

This is a light operated Relay circuit . Light Dependent Resistor(LDR ) is used to operate the switching Function of this circuit. This circuit is used to Switched on light At night Automatic and switch OFF in DAY light (sunlight) Automatic .

There is no need to switch on or off manually.

When Light is falling on LDR the Bulb is OFF and When at night when there is no light incident on LDR the Bulb is Switch ON Automatically.

darkness sensor ldr circuit

BC557 Pin diagram


Transformer 9-0-9 – 1

Bridge rectifier ic or 1N 4007 diode – 4+1= 5

Resistor 1K- 2,  220k – 2

preset -470k – 1

Transistor BC557 (PNP) – 1

BC547(NPN) – 1

Zener diode 8.2v (500ma) – 1

Regulator IC 7806 – 1

Relay 6v – 1

LDR – 1

LED – 2

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