Abstract: Provided is a power supply device, provided for a light source device which has a plurality of light-emitting bodies. The power supply device includes a circuit for controlling a current supplied to the light-emitting body. The power supply device also includes a control circuit for controlling a current from a power supply source, the control circuit being disposed at the central portion of the light source device. The power supply device additionally includes a cooling component capable of cooling surroundings by channeling a refrigerant, where the cooling component is provided on a back side of the light-emitting body. The power supply device also includes a heat transfer component connecting the cooling component and the control circuit to each other. The power supply device further includes an insulating component interposed between the heat transfer component and the control circuit at a state in contact with both.

Abstract: A power supply device, a photochemical reaction device and method in which the power supply device is used, and a lactam production method in which the photochemical reaction method is used, the power supply device being characterized by having a control circuit for controlling the current from a power supply source, a cooling means capable of cooling the surroundings by channeling a refrigerant, a heat transfer means connecting the cooling means and the control circuit to each other, and an insulating means interposed between and in contact with the heat transfer means and the control circuit. It is possible to prevent an excessive increase in temperature of the control circuit, stably maintain the function of the control circuit, and extend the lifespan of electric and electronic components mounted on the control circuit.

Abstract: Provided are a three-phase AC/DC converter disposed between a three-phase AC power supply and a light emitting diode group, the converter including a three-phase full bridge circuit in which pairs of switching elements are connected in parallel between DC buses for the three phases of the three-phase AC power supply; reactors connecting connection portions between the switching elements and corresponding phases of the three-phase AC power supply; a smoothing capacitor on the output side of the three-phase full bridge circuit; a DC voltage detection means; a power supply voltage phase detection means; and a pulse width modulation means for outputting pulse width modulation signals of the switching elements, wherein the pulse width modulation means outputs the pulse width modulation signals based on a power supply voltage phase and an output voltage between the DC buses.