Abstract: An LED traffic signal having a single switching power supply placed inside the load switch to supply power to each of the aspect signals. The traffic signal has several aspects, such as red, yellow and green. The load switch comprises a switching power supply to supply power to the signals, an output selection circuit to select the desired aspect, and a conflict monitor interface circuit to mimic an incandescent circuit.

Abstract: In a control system for controlling traffic signal lights, normally supplied with power from the AC source, the combination comprising flasher means electrically connectible to the lights to cause the lights to come ON and OFF, repeatedly, an electrical power storage device electrically connectible to the flasher means for supplying electrical power to operate the flasher means when AC source power is not supplied to the traffic control system, and a charging device for charging the storage device when AC power is normally supplied to the traffic control system.