Automatic light operated controlled switch circuit using ldr is very interesting circuit idea.
Automatic light on off circuit using ldr.
A simple dc motor electrical project.
During night the ldr gives a high resistance as a result the voltage passing through the base will become less than 5v so the led glows.
The transistor q1 will drive the transistor q2 to turn on the relay.
Circuit diagram of automatic street light controller switch circuit components used in this circuit.
Power supply 12v 1.
Ldr light dependent resistor relay.
The lights are turned on if the light is below a specific value.
Here we have used an ac bulb as street light.
Light intensity falling on ldr is less.
The system is highly sensitive.
Along with these a few more components are also used.
When light is low.
Ldr detects the light.
It automatically switches off lights when sunlight fall on it i e on ldr e g in morning by using a sensor called ldr light dependent resistor which senses the light just like our eyes.
This turns led off.
The automatic street lights using ldr work according to the light.
This circuit is very simple circuit and can be built with transistors and ldr you don t need any op amp or 555 ic to trigger the ac load.
During day time ldr gives a low resistance as a result the voltage through base is greater than 5v which switches the current to the emitter.
Some applications of this circuit are street light controlling home office light controlling day and night indicators etc.
When intensity of light that falls on the ldr is less resistance of the ldr is high and this causes more voltage drop across ldr.
Working of automatic street light project using ldr with arduino arduino.
You can use this for automatic light switch for street light.
By this light activated switch in day light will automatically switched off and at night switch on light.
When there is light on the ldr the resistance increases then there will be low at base of the transistor q1 then the transistor acts as off switch and turns off the relay.