Hon Hai Precision Industry Co., Ltd.

Hong-fu Jin Precision Industry (shenzhen) Co., Ltd.

Chun-Lung Hung

Wen-Ming Chen

Jing Liu

Wang-Chang Duan

Shi-Ming Zhang

Pei Jian Liu

De-An Zhang

Jie Liu

Kun Huang

Shao-Lin Zhang

Qiang Huang

Hai-Long Cheng

Lu-Qing Meng

Kuo-Pin Lin

A power management circuit comprising a power-on signal input, an output terminal a control unit, a switching unit, and a discharge unit. The control unit configured to selectively turn on the switching unit to output a power-on signal to a display module and selectively turn off the switching unit to cut off an electrical connection between the power-on signal input and the output terminal. The discharge unit configured to discharge residual electrical charges in the display module when the switching unit is turned off.

Power management circuit and liquid crystal display using same

An audio and video (AV) apparatus includes a player module for playing audio and video files, generating audio and video signals, and an internal display and an internal speaker. The AV apparatus further includes: a first switch for generating first instructions; an output module for being externally connected to output the audio and video signals; and a control module connected to the first switch. The control module being configured for disabling the internal display and internal speaker at receiving the first instructions at a situation that the output module is externally connected to output the audio and video signals, and disabling the internal display while keeping the internal speaker enabled at receiving the first instruction at a situation that the output module is not externally connected. A method for controlling the audio and video apparatus is provided as well.

Audio and video apparatus and method for controlling the same

An audio device includes a jack, a switch, an amplifier, an internal sound producer, and a determining circuit. The jack establishes a connection with an external sound producer. The switch is in an opened state when the connection is established, and in a closed state when the connection is open. The amplifier amplifies audio signals to amplified audio signals and sends the amplified audio signals to the switch. The determining circuit receives the amplified audio signals from the switch, and generates a high voltage to control the amplifier not to output the amplified audio signals to the internal sound producer when the switch is in the closed state, and generates a low voltage to control the amplifier to output the amplified audio signals to the internal sound producer. The determined circuit further filters out the amplified audio signals when the switch is in the opened state.

Audio device

An audio apparatus includes an input, a first resistor, a first capacitor, an amplifier, a second resistor, a second capacitor, and an output. The input is used for inputting audio signals. The first resistor and the amplifier are serially connected to the input; wherein the first resistor is connected to the inverting input of the amplifier and the non-inverting input of the amplifier is connected to ground. The first capacitor has one end connected to a node between the first resistor and the inverting input of the amplifier, the other end connected to ground. The second resistor has one end connected to a node between the first resistor and the inverting input of the amplifier, the other end connected to the output of the amplifier. The second capacitor is connected between the inverting input and the output of the amplifier. The output is connected to the output of the amplifier, for outputting the audio signals after processing.

Audio apparatus

An exemplary electronic device includes a controller, a first convertor, a second convertor, and a switching unit. The first convertor is configured for receiving a first voltage from an external power supply and converting the first voltage into a second voltage. The controller is coupled to the first convertor for generating a start signal when receiving the second voltage. The second convertor is connected to the controller for receiving the first voltage, converting the first voltage into a third voltage to power an operating unit of the electronic device, and converting the first voltage into a fourth voltage to power the controller when receiving the start signal. The switching unit is coupled to the controller and the first convertor for disabling the first convertor when the controller receives the fourth voltage. A related power supply unit is also provided.

Electronic device and power supply unit thereof

An electronic device includes an integrated circuit, a power interface, and an interface circuit connected between the integrated circuit and the power interface for protecting the integrated circuit from being damaged by electrostatic discharge. The interface circuit includes a current limit unit connected between the power interface and the integrated circuit for limiting an electrostatic discharge current and an electrostatic protection unit connected to a common node of the power interface and the current limit unit for clamping a voltage of the common node to a predetermined value. A related integrated circuit is also provided.

Power interface circuit and electronic device using the same

A power supply system for an electronic device includes a first and a second connector, a switch, and a controller. The first connector is used for connecting to a first power source. The second connector is used for connecting to a second power source, wherein the second power source is rechargeable. The switch establishes a connection between the first connector and the second connector so as to allow the first power source to charge the second power source. The controller detects a presence of the first power source and the second power source, and controls the switch to periodically establish the connection at the absence of the second power source, and to continuously establish the connection at the presence of the second power source.

Power supply system and protection method

An audio amplifier is provided. The audio amplifier includes an amplifier, a biasing circuit, and a time-delay circuit. The amplifier circuit is for amplifying audio signals. The biasing circuit is for providing a bias voltage to the amplifier circuit to actuate the amplifier circuit. The time-delay circuit is for receiving a pulse signal and delaying the bias voltage to avoid a sudden actuation of the amplifier circuit based on the pulse signal. The time-delay circuit comprises a first input for receiving the pulse signal, a first resistor coupled to the first input, a first output coupled to the biasing circuit, a first BJT whose base, emitter, collector are respectively coupled to the first resistor, ground, and the first output.

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Taipei Hsien, Taiwan

Chun-Lung Hung