High Intensity Discharge lamps (HID) used for urban street light are based on principle of gas discharge, t...
High Intensity Discharge lamps (HID) used for urban street light are based on principle of gas discharge, thus the intensity is not controllable by any voltage reduction method as the discharge path is broken.
In this project White Light Emitting Diode (LED) replaces the HID lamps where intensity control is possible by Pulse Width Modulation (PWM). The intensity control helps in saving energy at late nights during which the traffic density is low.
A programmable microcontroller from 8051 family is engaged to provide different intensities at the different times of late night for energy saving. The intensity gradually decreases from full intensity and then finally OFF.
The power supply consists of a step down transformer 230/12V, which steps down the voltage to 12V AC. This is converted to DC using a Bridge rectifier. The ripples are removed using a capacitive filter and it is then regulated to +5V using a voltage regulator 7805 which is required for the operation of the microcontroller and other components. For more info visit *******efxkits****; *******www.facebook****/edgefx