The first color light signal utilizing LED, which has enough brightness to secure 600 m of visibility, consumes only 14 Watt of power and has an extended service life of 30,000 hours, was used by JR-West for the restoration work after the Great Hanshin Earthquake of January 17, 1995, instead of conventional incandescent light bulbs.
Although more proof of the LED signal's characteristics may be needed for a while before its use is extended nationwide, its introduction was a major event.
Fig. 12 and 13 show the LED-type color light signal and the fundamental circuit of the LED unit, respectively. The LED unit has two circuits for each lamp, and if a circuit malfunctions, the brightness of the lamp is halved and an alarm is sounded by detecting the voltage of the lamps.
