Automatic controls for lighting, common in commercial buildings, are now available in a variety of options for residences ranging from a simple outdoor light fixture with a built-in photosensor to whole-house programmable controls that can activate lights for various scenarios (e.g., time of day, vacations, entertaining) from a central command center. Once a luxury for the wealthiest homeowners, centralized lighting controls are now affordable to the average homeowner.
Controls can switch lights on and off, or dim lights based on input from sensors which include simple timers, occupancy sensors to detect motion or infrared radiation from a person, or photosensors which operate lights or adjust light levels based on the amount of available daylight. There are also sensors, suitable for accessibility, that operate lighting by voice or sound. Many systems include the option of remote control via phone, computer, or a standard remote control.
Controls can be hard-wired or wireless. Most hard-wired controls rely on low-voltage CAT-5 wiring for signal transmission. However, there are a few products on the market that transmit signals over standard household wiring (and therefore require no additional wiring). Some systems are "plug and play" while other systems - typically ones that provide the most flexibility - require design and programming by the installer. All whole-house systems require some user programming, although programming can be as simple as programming a preset radio station in the car.
Central lighting control systems can be "zoned" to provide pre-programmed lighting levels (often called "scenes") for different situations. Examples of modes that may be preprogrammed include: vacation, dining, entertaining, and morning.
A manual-on occupancy sensor is a wall switch that will allow regular on and off switching of lights and can be used as an electronic occupancy sensor, as well. The occupancy sensor operates on low frequency sound waves that can sense movement in an area. After a prescribed time delay of six to fifteen minutes, dependent upon manufacturer, the sensor will turn off the light if movement has not been detected.
Dimmer switches can allow one fixture to serve several lighting functions, such as task lighting at full ballast and decorative or safety lighting on a lower setting. Dimming increases lamp life and saves energy - a light that is dimmed by 25% uses about 20% less energy while lamp life is increased fourfold.
One wireless controller, ideally suited for retrofit, works with a transmitter and receiver located in the same room. The transmitter is a push-button switch that generates its own electricity when pressed (and therefore does not require a separate power source such as batteries). The receiver is either an electrical outlet or a hard-wired device, and the light source (or any connected electrical device) can be toggled on or off via the transmitter switch. A single device or a group of electrical devices can be controlled via the toggle switch.