| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power source device in which a voltage across a capacitor for drive is secured even when performing operation according to a PWM signal, and to provide a lighting fixture. <P>SOLUTION: The power source device 1 includes a back converter composed of: a series circuit consisting of the first switching element Q1 and a diode D1, which is connected across the output terminals of a DC power source E; and a series circuit consisting of an inductor L1 and a capacitor C1, which is connected across both ends of the diode D1. A control circuit 2 switches on or switches off the first switching element Q1, using the capacitor Cs for drive as a power source. The second switching element Q2 which constitutes a charging path from a capacitor Cc for charge to the capacitor Cs for drive when switched on, is connected across both ends of the diode D1. The second switching element Q2 is switched on just before the start of an ON period in every ON period of ON-OFF drive periods of the first switching element Q1. <P>COPYRIGHT: (C)2011,JPO&INPIT |
