| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that the loss increases as a current into a discharge resistor increases when the discharge resistor is connected in parallel with a filter capacitor. SOLUTION: When an AC current is supplied from the external commercial power supply, a DC current is effectively supplied to the internal devices by providing a discharge circuit to the power supply circuit and switching a discharge path or non-discharge path of a relay circuit with a switching transistor circuit depending on the ON and OFF states of the AC current inputted from the external commercial power supply. Meanwhile, when the AC current is turned OFF, charges stored in the first filter capacitor are quickly lowered to 0 V through a discharge resistor. Accordingly, it can be prevented that even if a power supply cable is disconnected, an LCD provided to a HiFi deck is lighted and an input from a remote controller is accepted.
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