| 摘要 |
<p>A telephone service provider or alarm company, supplies phone-line-power for auxiliary, backup, and/or emergency lighting in residential, commercial and/or industrial facilities at a reasonable charge in exchange for providing, maintaining and ensuring that lighting service and power will be available when needed such as under power failure situations. A phone-line-driven lighting device includes a sensor capable of detecting a primary power source. Once the sensor senses that the primary power source is not present, circuitry connects the device's phone line terminal to a light producing element, in turn powering the light producing element via a telephone line's DC or AC power. Such a device may include a control circuit which responds to a predetermined phone line signal, thereby controlling the operational state of the device. Such a signal could be broadcast in emergency or other informative situation by the provider of the phone line service.</p> |
