| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply device which prevents a rush current even without a series resistor and balances the voltage of a capacitor. SOLUTION: The power supply device includes: a series circuit of capacitors wherein the capacitors are connected at a first connecting point and which is connected in parallel to a DC power supply; a series circuit of switching elements wherein the switching elements are connected at a second connecting point and which is connected in parallel to the DC power supply; a single-phase full-wave diode bridge with one end of its AC input terminal connected to the first connecting point and the other end connected to the second connecting point; a third capacitor connected between DC output terminals of the single-phase full-wave diode bridge; a resistance load connected in parallel to the third capacitor; and a driving control section for controlling driving of the series circuit of switching elements. Each switching element includes emitter resistors (12 and 13). The driving control section includes a voltage detecting section (21) for detecting a voltage difference between the intermediate voltage of the DC power supply and the voltage of the first connecting point, a PWM signal generating section (28) for comparing the voltage difference and triangular waves to generate a PWM signal, and gate driving sections (32 and 33) for driving the switching elements. COPYRIGHT: (C)2009,JPO&INPIT
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