Examples include programmable setback thermostats, motion detectors, occupancy sensors, photocell lighting controls, and timers. Individual control devices have a wide variety of successful applications. These range from outdoor lighting to security sensors. The familiar television remote control unit often falls into this category. This makes it easier to retrofit the system into existing homes.
Users can use a television set to monitor the system s status.
Compatible appliances are necessary, but currently it is up to the individual manufacturers to decide how to make them compatible. Individual semiconductor manufacturers have developed microchips that could be installed in appliances. A centrally controlled communication system routes signals between a central computer and appliance controllers or environmental sensors. If the controller fails, however, the whole system fails. A central control system allots incoming household electricity to a distribution unit in each room of the house.