Main objective of Automatic Street light control using LDR project is to implement an intelligent automatic street control system using LDR. The control circuitry is designed with an AT89C51Micro controller used for manipulating the IR sensors and switching operations of the circuit.
Automatic street light controller circuit:
Here we use a light dependent resistor to senses the variations in the intensities of the sun light around the atmosphere, the main principle behind the LDR is the intensity of the light is directly proportional to resistance i.e. whenever there is enough light it acts as an insulator and when the intensity levels dropped it acts as mere conductor, the infra red sensors place on either side of the road are activated by the micro controller based up on the digital signals from the A/D converter, the A/D converter takes the analog signals from the LDR and converts them into digital pulses for micro controller.
For over view on circuit diagram, block diagram and simulation details view Youtube video link.
Hardware components of the proposed circuit:
Power supply circuit:
The street light power saving unit operates at 5v dc supply for that we provide a circuit assembly of step down transformer, full bridge rectifier, filter, and LM7805 regulator three terminal voltage regulators for sequential operations from 230v ac supply – 12v ac supply – ripple less 12v dc – regulated 5v dc.
AT 89C51 Micro controller:
An Atmel non-volatile memory Programmed low power high performance micro controller is used in this project which is programmed using embedded c programming language.
The sensing circuit has LDR and the senses the periodic regulation of sunlight.
Two IR sensors:
The two IR sensors activates based up on the micro controller commands.
Download Automatic Street Light Control Using LDR Project Report