Patent ID: 7696698

Claim:
A signal that provides light output for automotive, rail, ship traffic and/or illumination control, comprising: a light emitting diode (LED) array, wherein the LED array includes three groups of disparate colored LEDs; and a power supply unit that provides independent power to each of the three LED groups, for each LED group the power supply unit includes, an input controlled switch connected to a power line to provide power to the LED array; an input under voltage/over voltage circuit for monitoring the voltage level of the power line and for enabling and/or disabling the input controlled switch according to the voltage level of the power line; a flyback transformer that converts the power received from the power line from an alternating or a continuous current signal to a direct current signal output to the LED array; a dummy load that draws power additional to the LED array; a dummy load detection circuit that monitors the dummy load to insure that the power drawn by the load is greater than or equal to a predetermined threshold; and a light out detection circuit that monitors the light output of the LED array via an optical sensor.