Patent ID: 7893558

Claim:
An on-vehicle power supply device, comprising: a first switch module, for receiving a direct current (DC) input power supplied by a vehicle battery, and converting the DC input power into a first high-frequency power; a rechargeable battery, for storing and supplying a backup power; a second switch module, containing a first transistor and a second transistor and being a bi-directional switch module, electrically connected to the rechargeable battery for receiving the backup power, and converting the backup power into a second high-frequency power; a power controller electrically connected to each of the first switch module and the second switch module, for detecting the DC input power to control operations of the first switch module and the second switch module, in order to ensure either the first high-frequency power or the second high-frequency power is outputted at a time, and for switching a state of the second switch module according to whether the DC input power is provided from the vehicle battery; an isolation transformer, electrically connected to the first switch module and the second switch module, for receiving the first high-frequency power or the second high-frequency power to produce a plurality of high-frequency voltages; at least one first output unit, electrically connected to the isolation transformer, for receiving the high-frequency voltage, and converting the high-frequency voltage to an alternating current (AC) output voltage; at least one second output unit, electrically connected to the isolation transformer, for receiving the high-frequency voltage, and converting the high-frequency voltage to a DC output voltage; and a filter electrically connected to the power controller and the first switch module, for suppressing noises of the DC input power at the instant moment of starting a car engine; wherein when the power controller detects an input of the DC input power, the power controller is configured to turn off the first transistor and the second transistor of the second switch module so that the rechargeable battery is charged by the DC input power when the first switch module converts the DC input power into the first high-frequency power, or otherwise turn on the first transistor and the second transistor so that the second switch module receives the backup power from the rechargeable battery DC input power before the second witch module converts the backup power into the second high-frequency power.