| 摘要 |
PURPOSE:To easily reduce a leakage current so that an EMI characteristic can be kept within a prescribed value even after a system has been constituted by installing a changeover selection means wherein whether a frame ground for a switching power supply is to be connected to a frame ground for a power- supply circuit is selected. CONSTITUTION:When a toggle switch 8a is short-circuited, a frame ground 10a for a device 4a is connected to a frame ground 9a for a switching power supply 5a, and, when it is released, the frame ground 10a is released from the frame ground 9a. On the other hand, when a toggle switch 8b is short-circuited, a frame ground 10b for a device 4b is connected to a frame ground 9b for a switching power supply 5b, and, when it is released, the frame ground 10b is released from the frame ground 9b. Consequently, the toggle switches 8a, 8b are turned on and off so that the leakage current of a system becomes minimum under a condition that an EMI characteristic is within a prescribed value. |
