LED ILLUMINATION SYSTEM

PROBLEM TO BE SOLVED: To provide a technique for operating a lighting condition of a plurality of LED illumination devices with one dimmer.SOLUTION: The LED illumination system includes: an LED illumination device; a dimmer connected to the LED illumination device via a pair of two first feeder cables for supplying a driving current and operating a lighting condition of the LED illumination device; and a relay device connected to a pair of two second feeder cables connected to the first feeder cables for supplying the driving current to the other LED device. The relay device includes: an inter-step coupling circuit for detecting a pulse-like driving current flowing in the first feeder cables and to be supplied to the LED illumination device; a direct current power source; and a driving device for generating the pulse-like driving current with a shape similar to a waveform of the pulse-like driving current flowing in the first feeder cables and outputting it to the second feeder cables using a direct current from the direct current power source with the pulse-like driving current detected by the inter-step coupling circuit as control signals.