APPARATUS AND METHOD FOR TRAFFIC SIGNAL POWER FAILURE

摘要

An alternative emergency power supply for LED traffic signal lights. The power supply includes an alternative power source, a power state detector, a circuit transfer switch, and a blink cycle timer and can be mounted on or in a traffic signal head. The power state detector can differentiate between a power failure in a traffic head and a main power supply failure. Upon a power failure, the LED traffic signal light and the alternative power source are disconnected from the main power supply lines. The LED traffic signal light may be 8 or 12 inches in diameter having an S-base, screw-in or Type II design and is placed into a flash mode for between about 12 hours and about 24 hours, or until normal power is restored. A coded signal is communicated to provide indication of a true main power supply failure.