| 摘要 |
The disclosed auxiliary power device for a vehicle is capable, without an increase in size, of starting even when the battery output voltage has dropped. An emergency power source starter device (100) for supplying power in place of a battery is configured from a switch circuit (200) which supplies power from an overhead line (1) when the output voltage of the battery has dropped, a DC step-down circuit (300) which divides and outputs the overhead line voltage inputted through the switch circuit (200), and a converter (26) which inputs the voltage output from the DC step-down circuit (300) and outputs the same DC voltage normally output by the battery. The DC step-down circuit (300) is configured from a switching element (18), a series resistance (13) connected between the collector of the switching element (18) and the switch circuit (200), and a smoothing capacitor (19) connected to the emitter of the switching element (18). The conduction ratio of the current flowing through the series resistance (13) is controlled depending on the output voltage value of the DC step-down circuit (300), and the output voltage of the DC step-down circuit (300) is kept at a constant value. |
