DIMMING UNIT FOR LIGHTING SYSTEM

摘要

PROBLEM TO BE SOLVED: To simply light a lamp when light does not light up due to a failed circuit within a control unit and the like, and easily make clear causes for lighting failure by outputting rated voltage to an electric discharge lamp by means of an inverter device when a circuit for electrical wiring is cut off by a switching means. SOLUTION: When both a dimming signal outputting part 19 and a dimming signal amplifying circuit 18 are out of order, an electric discharge lamp keeps a condition that the light is turned off. In order to avoid the aforesaid condition, a jumper wire 8 is disconnected. This action thereby permits a current value corresponding to a voltage wave form which is supposed to be transmitted from the outputting part 19, to be outputted as is to an inverter 3 by the circuit 18, and voltage capable of surely lighting the lamp is thereby outputted to the electric discharge lamp 4. When the wire 8 is connected therewith, the electric discharge lamp 4 is controlled based on a set dimming value by the inverter 3, and when the wire 8 is disconnected therefrom, it will never fail that the electric discharge lamp 4 is lighted up. Therefore, the wire 8 within a control circuit switched to a conductive state, can be simply disconnected therefrom, and the electric discharged lamp can be lighted up with the wire 8 disconnected when the circuit fails. In addition, it is simply made clear whether the cause for no lighting is the failure of the circuit or the life of the electric discharge lamp.