The present invention is directed to lighting control systems and more particularly to a system for controlling electric lights in such a manner as to minimize energy consumption. 
In view both of the worsening energy shortage and of the consequent rise in energy costs, it is becoming ever more important to eliminate energy waste.  One of the most common types of energy waste results from the widespread practice of neglecting to turn off electric lights when they are not needed.  In particular, many people habitually enter a room, turn on a light, and then leave the room without turning the light off.  It is not uncommon for a large percentage of the lights in a house or apartment, for example, to be on at one time, even if only one room is occupied and the other rooms are vacant.  This problem is not limited to residential buildings, but is also frequent in commercial, industrial, health-related and other facilities.