| 摘要 |
LEDs that provide street illumination are used to create emergency signals. This facilitates simple retrofitting of existing streetlighting infrastructure. In one embodiment, a streetlight comprises an LED set that itself comprises or consists of a plurality of LEDs collectively producing a white light output. The streetlight also includes a receiver for receiving a signal of an alarm condition, and a controller for (i) disabling the LED set during a daylight period, (ii) maintaining the normal operating mode during a lighting period distinct from the daylight period, and (iii) in response to the alarm condition detected by the receiver, de-activating at least one of the LEDs to produce a non- white (e.g., red or amber) output signaling the alarm condition. |
