12v Ldr Relay Circuit. This automatic street light controller circuit uses an ldr light dependent resistor which is responsible for detecting light and darkness. Circuit diagram working explanation.
You can use this for automatic light switch for street light. Ldrs or light dependent resistors are very useful especially in light dark sensor circuits. The more light less resistance and less light more resistance.
The bridge rectifier circuit uses a step down transformer to step down the voltage from 230v into 12v.
Here two bc547 npn transistors are used to operate the relay. An ldr or light dependent resistor is a resistor where the resistance decreases with the strength of the light. Convert into light detector this circuit just like the previous two circuit operate as dark activated switch. The circuit uses a light dependent resistor ldr to sense the light when there is light the resistance of ldr will be low.
