US Patent 9107269 Emergency lighting device

An emergency lighting device includes a backup power supply for illuminating a light during a power loss. The lighting device includes a transmitter, which transmits a signal to a receiver during a power outage. When the receiver receives the signal, the source of power switches from the primary power source, e.g., AC utility power, to a backup power source, e.g., DC battery power. The lighting device may include an LED lamp in which AC-LEDs are selectively illuminated when primary power source is delivered and DC-LEDs which are selectively illuminated during a power outage.