To enable to rotate a dimming light suspended at a high place in a panning direction and in a tilting direction or the like by a wireless remote controller without using an outlet of AC 100 V.

The arm unit 50 of the dimming system is provided with a receiving part (an antenna 54 and a communication module 55) for receiving a control signal transmitted from the wireless remote controller 30 for making a dimming light 1 carry out panning/tilting/focusing operations, a C type 20 A plug 7a free in inserting into and removing from the outlet 6 for a lighting power supply connected to a dimming control panel 10, a common outlet (a C type 20 A outlet 51) to which a C type 20 A plug 2a drawn out from the dimming light 1 can be connected, and in which the lighting power supply inputted from the C type 20 A plug 7a is branched to the external dimming light 1 side and the internal circuit side, and a lighting power supply conversion circuit 53 in which the lighting power supply inputted from the C type 20 A outlet 51 is supplied to the internal DC driving circuit by being converted into a DC driving signal.