| 摘要 |
PURPOSE:To provide a power supply circuit equipped with a ripple filter in which voltage loss can be reduced without sacrifice of battery life. CONSTITUTION:The power supply circuit comprises an external power supply jack 4 to be inserted with output plug of an AC adapter, first switch means 4A, 4B which are turned OFF upon insertion of the output plug into the external power supply jack 4, a second switch means 31 to be turned ON upon insertion of the output plug into the jack 4, and a ripple filter 5. The external power supply jack 4 is provided with an input contact 4P which is connected with the output plug upon insertion thereof. An incorporated battery 3 is connected through the first switch means 4A, 4B with feeder line of a main circuit 1. The input contact 4P of the external power supply jack 4 is connected through the series circuit of the second switch means 31 and the ripple filter 5 with the feeder line of the main circuit 1. |
