| 摘要 |
PURPOSE:To hold constantly the auxiliary electric power source of a DC-DC converter to charged condition by a method wherein the first and the second switching means are provided, and the second switching means is controlled by a switch to interrupt the auxiliary electric power source. CONSTITUTION:When a switch 7 is made to ON, a voltage is supplied from the auxiliary electric power source 6 to an exciting coil 3B of the second switching means 3 through the switch 7 and a voltage stabilizing circuit 10, and a contact 3A is closed. As a result, because a voltage is applied from the main battery 1 to an exciting coil 2B of the first switching means 2, a contact 2A is closed. Accordingly because the voltage is supplied from the main battery 1 to a converting circuit 4, DC-DC conversion is performed and the auxiliary battery 6 is charged. |
