Abstract: A wireless power transmission device includes a transmitter unit and a receiver unit. The transmitter unit converts an input DC power into an inverted AC power, the receiver unit receives the AC power through a coupling effect. A fault protection method is also provided in the present disclosure. If the receiver unit is abnormal, a main power circuit of the receiver unit is short-circuited. Then, a phase relationship between an inverted AC voltage and an inverted AC current of the inverted AC power is detected. A phase judgment signal is generated according to the phase relationship. An overcurrent judgment signal is generated according to the amplitude of the inverted AC current and a predetermined current threshold. A fault signal is generated according to the phase judgment signal and the overcurrent judgment signal. In response to the fault signal, the wireless power transmission device is controlled to shut down.

Abstract: A power generating method for a wireless power transmission device includes the following steps. Firstly, a power transmitting circuit is switched between an enabled state and a disabled state. When the power transmitting circuit is in the enabled state, the power transmitting circuit emits a first power and the power receiving circuit converts the first power into a second power. Then, the second power is converted into an output power, and the second power is converted into an auxiliary power. If the first power is not received by a power receiving circuit, the above steps are repeated. If the first power is received by the power receiving circuit, the power transmitting circuit is continuously in the enabled state, so that the auxiliary power is continuously generated.

Abstract: A control circuit for a wireless power transmission device is provided. The wireless power transmission device includes a transmitter unit and a receiver unit. The control circuit includes a transmitter detecting unit, a first control unit and a driver unit. The transmitter detecting unit obtains an input power of the transmitter unit and generates an input power signal. The first control unit generates a control signal according to a result of comparing the input power signal with a reference input power signal. The driver unit drives switching devices of the transmitter unit according to the control signal. Consequently, the input power of the transmitter unit is adjusted, and an output ripple or a magnitude of the output of the receiver unit is adjusted.

Abstract: A wireless power transmission device includes a contactless transmitter unit, a contactless receiver unit and a step-down transformer. The transmitter unit receives an input AC power. A receiver coil of the receiver unit and a transmitter coil of the transmitter coil are electromagnetically coupled with each other. The input AC power is electromagnetically coupled to the receiver coil through the transmitter coil. Consequently, the input AC power is converted into a first output AC power. A first coil and a second coil of the step-down transformer are electromagnetically coupled with each other. The first coil is electrically connected with the receiver coil to receive the first output AC power. A second output AC power is outputted from the second coil. A turn ratio of the first coil to the second coil is larger than a turn ratio of the transmitter coil to the receiver coil.