| 摘要 |
PROBLEM TO BE SOLVED: To provide a direct-current power supply device that simplifies a protective circuit for a converter circuit, and reduces footprint, cost, and loss. SOLUTION: The converter circuit is obtained by parallel-connecting a series connection circuit in which two inverse-parallel connection circuits of switching elements 3a, 3b and diodes 4a, 4b are connected in series, a series connection circuit in which diodes 4c, 4d are connected in series, and a capacitor. A reactor 2 is connected between the point of junction between the switching elements 3a, 3b and an alternating-current power supply and the converter circuit includes a switching element overcurrent detecting means 10 and a switching element controlling means 9. Overcurrent passed through the switching element 3a is determined using a detection value obtained from a current detector 5 and overcurrent passed through the switching element 3b is determined using a detection value of the voltage across a shunt resistor 6a. Thus they can be protected at a common GND potential. Accordingly, the protective circuit can be simplified and footprint, cost, and loss can be reduced. COPYRIGHT: (C)2009,JPO&INPIT
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