| 摘要 |
In a power supply (AC adapter etc.) of an electronic device, a first Y capacitor and a second Y capacitor are connected in series between two AC input lines which are connected to an input AC cable of the power supply so that input AC voltage will be divided, and a third Y capacitor for the prevention of EMI (Electro-Magnetic Interference) is provided between a grounding line on the secondary side of a transformer of the power supply and the connection point between the first Y capacitor and the second Y capacitor. The capacitance of the second Y capacitor is set larger than that of the first Y capacitor and the second Y capacitor having the larger capacitance is connected to a neutral-side AC input line which is connected to the neutral terminal of an AC socket. Due to the capacitance difference between the first Y capacitor and the second Y capacitor, voltage difference between metal part of the electronic device and the ground is reduced, and thereby the electric shock problem of the electronic device is eliminated or reduced considerably. The reduction of the electric shock problem can be attained without deteriorating the portability of the electronic device and the EMI prevention capability.
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