LIGHT-EMITTING DIODE TYPE SIGNAL LAMP UNIT

PROBLEM TO BE SOLVED: To provide an LED type signal lamp unit capable of carrying out natural light adjustment without any discomfort, with appropriate light adjustment in accordance with exterior light. SOLUTION: The LED type signal lamp unit 10, to supply power to an LED, emitting lamp light for signal by rectifying a commercial power source P, is provided with a full-wave rectifier 30 rectifying the commercial power source P, a constant current part 40, and a light control part 50. The constant current part 40 is to supply power to the LED by receiving an output of the full-wave rectifier 30 and applying a reference voltage by a constant voltage element 41 on an output semiconductor 45. The light control part 50, arranged so as to be interposed between a reference voltage end A of the constant voltage element 41 in the constant current part 40 and the output semiconductor 45, is equipped with a photosensor 55 detecting exterior light and an amplifier 51, amplifies an output of the photosensor 55 by the amplifier 51, applies a voltage equivalent to the reference voltage on the output semiconductor 45 in the daytime, and applies a voltage lower than the reference voltage on the same after dark, by the above, the LED light is adjusted by varying outputs of the constant current part 40. COPYRIGHT: (C)2006,JPO&NCIPI