| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent an overvoltage from being applied to a load when a battery is removed in a DC power supply device for supplying power to the battery and the load by using an AC generator as a power supply. <P>SOLUTION: A DC power supply device controls supply of a trigger signal to thyristors Th1, Th2 of a control rectifier circuit 2 so as to maintain a voltage between DC output terminals 2c, 2d at or below an adjusted value. The DC power supply device includes a trigger control circuit 6D operated when an overvoltage is generated, and a bypass switch 6E. When the voltage between the DC output terminals 2c, 2d exceeds an overvoltage set value set to a higher value than the adjusted value, the trigger control circuit executes control for preventing supply of the trigger signal to the thyristors of the control rectifier circuit 2. When a voltage, having a polarity which makes a potential of a negative DC output terminal 2d higher than that of a positive DC output terminal 2c, is applied between the DC output terminals 2c, 2d from the side of a load 4, the bypass switch allows a bypass current to flow from the side of the negative DC output terminal to the side of the positive DC output terminal so as to prevent a current from flowing into the control rectifier circuit 2 from the side of the load 4. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
