| Abstract |
Control of illumination of level in the street lighting always remains a problem for fluctuating ambient condition due to fog, smog, haze, etc. Advancement in power electronics for large power control alongwith microelectronics make it possible to suggest schemes for illumination level control in the street lighting. Some special control characteristics can also be incorporated into such an automatic control scheme. This paper suggests a thyristor controlled power electronic scheme for automatic control of illumination and ON-OFF of street lights suitable for SON lamp. Power to SON lamp is fed via thyristor power electronic controller, operating in a closed loop feed-back circuit. The feedback circuit consists of a balanced bridge with LDR in one arm, which sets the desired illumination level. Any deviation from the set illumination level due to ambient conditions gives an actuating signal to the thyristor controller via trigger circuits. The operation is such that any reduction of ground illumination level will increase the voltage to the SON lamps so that the ground illumination always remain constant within a tolerable limit. The other feed-back loops actuates the ON and OFF conditions of the SON lamps. |
