CONSTRUCTION OF TWILIGHT CONTROL CIRCUIT USING LDR, TIMER & RELAY Objectives of this experiment: 1. To construct twilight control using timer, LDR and to verify that when the ambient light around the LDR cell decreases the resistance of the LDR increases and the voltage at trigger input to the 555 decreases and causes the output to go high and it activates the relay. Built in regulated power supply: +12V/300mA Input Supply: 230 VAC/50Hz mains operated. Dimension: 27cms x 17cms x 10cms. Weight: 500gms Qty :