Nowadays highways are lightened by using High Intensity Lamps. The disadvantage of this High Intensity Lamps is that it consumes a lot of energy and another disadvantage of this is that the intensity cannot be varied according to the requirement. To overcome this limitation, this system “Automatic Light Intensity Controller by External Light Sensing Project” is developed. To overcome the limitations specified above, it makes use of LED’s (Light Emitting Diodes) as light source and simultaneously its intensity can be varied and controlled as per the need. The programmable instructions to control the intensity by producing pulse width modulated signals which drives a MOSFET to switch LEDs to achieve required results are fed into the 8051 family microcontroller. Our system also senses external lighting conditions to vary the light intensity. Based on external lighting conditions the intensity of inner lights is varied using PWM. So when external light is low, the light intensity is high and as external light increases our decreases to save power.

• Hardware Specifications

• 8051 Microcontroller

• LDR Sensor 5MM Photoresistor

• Resistors

• Capacitors

• Transistors

• Cables and Connectors

• Diodes

• PCB and Breadboards

• LED

• Transformer/Adapter

• Push Buttons

• Switch

• IC

• IC Sockets

• Software Specifications

• Keil µVision IDE

• MC Programming Language: C

Diagram