For purposes of this discussion, we are using the term light to refer to the type of bulb. The lighting industry uses the term "lamps" and all commercial catalogues and order forms will refer to a specific incandescent lamp or fluorescent lamp. In addition, home improvement stores may refer to lighting fixtures as lights and to light bulbs as bulbs.
Control equipment can alter light levels automatically over short intervals to correspond to the space activities and desired levels of illumination. Controls can potentially save considerable amount of energy used in your lighting system. There are several control components that can be used. These components may include:
A simple automatic timer controls when and how long a light stays on. The timer will turn lights on and off at prearranged time schedule. It can be located at a light switch, at the wall receptacle or in a light socket.
A photocell is a sensored compensator that measures and adjusts the illumination levels to a preset level in a designated area.
An occupancy sensor detects whether a space is occupied by sensing the motion of an occupant. These sensors can be ultrasonic, infrared or audio. They are an excellent way to save energy in rooms where lights are frequently left on. They are also popular outside, for walkways or security lights.
Dimmers are the switched compensators that allow you to manually adjust the intensity of light in a room. They can dim the light from 100 to 50 percent. They can be used with incandescent lights, including low voltage systems. They can also be used with new screw-based dimmable fluorescent bulbs. Other fluorescent lights must have their own dimmable ballasts (see below).
Solid state dimming ballasts
Solid state dimming ballasts operate fluorescent lamps and can dim them continuously with low voltage from 100 to 10 percent