An intelligent light control system for power saving

Saving energy has become one of the most challenging issues these days. The most waste of energy comes from the inefficient use of the electrical energy consumed by artificial light devices (lamps or light bulbs). This paper presents a system with detailed design for saving electrical energy by controlling the intensity of artificial light to a satisfactory level and getting use of the day light when possible with the best effort for energy saving. An improvement to daylight harvesting and controlled dimming systems is introduced while counting for over illumination cases. The idea behind is to control the venetian blinds or curtains in such a way to make use of the daylight if it is available. Otherwise, it uses the artificial internal building light. Controlling the amount of daylight passing inside is via controlling the opening angle of the venetian blinds while controlling the intensity of artificial light is by controlling the amount of power delivered to the lamp via Pulse Width Modulation (PWM) for DC lamps or clipping the AC wave for AC light bulbs. The system uses Controller Area Network (CAN) as the media of communication with the sensors and the actuators. The system is modular and can be expanded to span large buildings. The advantage of the design is that it gives the user a single point of operation which is the amount of desired light. The controller is responsible to determine a way to satisfy the amount of light desired with the least energy consumption. One of the major issues considered is the ease of installation and the low cost of the system components. The system shows a significant amount of energy saved and feasibility in practical implementation.