| 摘要 |
PURPOSE:To prevent a rush current by switching a power supply route to a relay by charging previously the power to be supplied to a capacitive load into a load via a semiconductor switch element and a resistance. CONSTITUTION:A power supply 1 supplies the power to a capacitive load 2 via a relay 4. An excessive rush current is produced when the relay 4 is closed. In this respect, a semiconductor switch element 5 is previously turned on, and a capacitor 3 is charged while a current is limited by a resistance 6. Then the relay 4 is closed when the capacitor 3 is charged up to a certain level. In this case, the element 5 and the realy 4 are controlled by a control circuit 7. Thus it is possible to prevent the rush current that is caused when the relay 4 is opened and closed. |
