An automatic light control system works by sensing the ambient light around the system and thus controlling the light. Automatically turning off during the day and turning on during the night. This system helps to reduce consumed energy and is designed for outdoor use such as street lights.
System Block Diagram
Fig: Block diagram of automatic dusk to dawn light controller
The sensor is the heart of the unit which senses the light of the surroundings. It then sends the collected data to the comparator which compares the received data with the one received from the reference voltage generator. With reference to the data the comparator commands the switching unit to either turn off or turn on the light as required.
Although for maintenance and ergonomic design one controller is suitable for one unit of light, the controller can also be extended to control other lights within a radius of 60 m from the installation spot.
Cost per Unit
The cost per unit depends upon the requirements. If the light is an AC one the controller costs NRs 700/- per unit. Whereas, to control DC lights it costs NRs 500/- per unit.
Also, costs will increase if the unit is to be placed within metal casings making it weather proof.