| 摘要 |
In the field of appliances connected to the power grid, it is sometimes desirable for such appliances (102) to function even in the absence of grid power. Example applications include emergency lighting or public address systems. It is sometimes further desirable that such appliances be controllable in the absence of grid power, for example responding to commands to turn on or off. Appliances are described that can function in the absence of grid power, yet remain under control of a switch (107), actuator, or other control device. A control device may be local or remote. Appliances may be controlled via power-line communication. Appliances may sense the state of a switch even where other appliances are connected on a local circuit. |
