LIGHTING DEVICE, ILLUMINATING FIXTURE AND ILLUMINATION SYSTEM

To provide a lighting device, an illuminating fixture and an illumination system capable of protecting a buck converter circuit.SOLUTION: A lighting device comprises: a first input terminal and a second input terminal supplied with a power from a DC power supply; a first DC supply line whose one end is connected with the first input terminal; a second DC supply line whose one end is connected with the second input terminal; a buck converter circuit connected with the other end of the first DC supply line and the other end of the second DC supply line, and that makes a light source emit light; a first diode provided on the first DC supply line and whose anode is connected with the first input terminal, or provided on the second DC supply line and whose cathode is connected with the second input terminal; and a capacitor provided between the first diode and the buck converter circuit, and that connects between the first DC supply line and the second DC supply line.SELECTED DRAWING: Figure 1 【課題】本発明は、点灯装置、照明器具および照明システムに関し、バックコンバータ回路を保護できる点灯装置、照明器具および照明システムを得ることを目的とする。【解決手段】本発明に係る点灯装置は、直流電源から電力の供給を受ける第１入力端子および第２入力端子と、一端が該第１入力端子と接続された第１直流供給線路と、一端が該第２入力端子と接続された第２直流供給線路と、該第１直流供給線路の他端と該第２直流供給線路の他端とに接続され、光源を点灯させるバックコンバータ回路と、該第１直流供給線路上に設けられアノードが該第１入力端子と接続された、または、該第２直流供給線路上に設けられカソードが該第２入力端子と接続された第１ダイオードと、該第１ダイオードと該バックコンバータ回路との間で、該第１直流供給線路と該第２直流供給線路とを接続するコンデンサと、を備える。【選択図】図１