Abstract: A leakage current suppression circuit is adapted for use with an AC-to-DC power supply that includes a bridge rectifier converting an AC input voltage into a DC voltage and outputting the DC voltage through a first output terminal and a grounded second output terminal thereof, a DC-to-DC converter converting the DC voltage into a predetermined DC output voltage and outputting the DC output voltage through a first output end and a grounded second output end thereof, and a capacitor coupled to the second output terminal of the bridge rectifier at one terminal thereof. The leakage current suppression circuit includes a first impedance unit and a second impedance unit each coupled in parallel between the other terminal of the capacitor and ground.

Abstract: An external power supply and a system connection detection unit applied thereto are provided. For providing DC power, the external power supply separably connects with a positive input terminal and a negative input terminal of a system through a positive output terminal and a negative output terminal respectively. When the positive output terminal and the negative output terminal are respectively connected to the positive input terminal and the negative input terminal, a system detection terminal connects with a system connection terminal of the system, and a connection status signal generated by the system connection detection unit switches the operation of the external power supply from a deep sleeping mode to a normal operation mode. The system connection terminal is electrically connected to one of the positive input terminal and the negative input terminal through at least a first resistive element.

Abstract: A leakage current suppression circuit is adapted for use with an AC-to-DC power supply that includes a bridge rectifier converting an AC input voltage into a DC voltage and outputting the DC voltage through a first output terminal and a grounded second output terminal thereof, a DC-to-DC converter converting the DC voltage into a predetermined DC output voltage and outputting the DC output voltage through a first output end and a grounded second output end thereof, and a capacitor coupled to the second output terminal of the bridge rectifier at one terminal thereof. The leakage current suppression circuit includes a first impedance unit and a second impedance unit each coupled in parallel between the other terminal of the capacitor and ground.

Abstract: An external power supply and a system connection detection unit applied thereto are provided. For providing DC power, the external power supply separably connects with a positive input terminal and a negative input terminal of a system through a positive output terminal and a negative output terminal respectively. When the positive output terminal and the negative output terminal are respectively connected to the positive input terminal and the negative input terminal, a system detection terminal connects with a system connection terminal of the system, and a connection status signal generated by the system connection detection unit switches the operation of the external power supply from a deep sleeping mode to a normal operation mode. The system connection terminal is electrically connected to one of the positive input terminal and the negative input terminal through at least a first resistive element.

Abstract: A resonant power converting circuit is provided, which includes a resonant converting unit, a control unit, a current detecting unit and a frequency modulation unit. The control unit outputs switching signals to the resonant converting unit to adjust an output thereof. The current detecting unit is configured to detect an output current of the resonant converting unit. The frequency modulation unit may adjust a lowest switching frequency of the control unit according to the detected output current so as to increase a gain of the resonant converting unit and an output stability of the resonant converting unit.

Abstract: A resonant power converting circuit is provided, which includes a resonant converting unit, a control unit, a voltage detecting unit and a frequency modulation unit. The control unit outputs switching signals to the resonant converting unit to adjust an output of the resonant converting unit. The voltage detecting unit is configured to detect an output voltage of the resonant converting unit. The frequency modulation unit may adjust a lowest switching frequency of the control unit according to the detected output voltage so as to increase a gain of the resonant converting unit and an output stability of the resonant converting unit.

Abstract: A power supply apparatus includes an open loop power switcher, a power isolation transformer, a backlight driving circuit, and a power circuit. The open loop power switcher converts a direct current (DC) power into an alternating current (AC) input voltage. The power isolation transformer is coupled to the open loop power switcher and includes a primary-side winding, a first winding, and a second winding, wherein the first and second windings are disposed at the secondary-side of the power isolation transformer, and the first winding is employed for generating a first voltage signal according to the AC input voltage. The backlight driving circuit is employed for driving a backlight module according to the first voltage signal. The power circuit is employed for receiving a second voltage signal generated from the second winding according to the AC input voltage, in order to generate an output power signal.

Abstract: A resonant power converting circuit is provided, which includes a resonant converting unit, a control unit, a current detecting unit and a frequency modulation unit. The control unit outputs switching signals to the resonant converting unit to adjust an output thereof. The current detecting unit is configured to detect an output current of the resonant converting unit. The frequency modulation unit may adjust a lowest switching frequency of the control unit according to the detected output current so as to increase a gain of the resonant converting unit and an output stability of the resonant converting unit.

Abstract: A resonant power converting circuit is provided, which includes a resonant converting unit, a control unit, a voltage detecting unit and a frequency modulation unit. The control unit outputs switching signals to the resonant converting unit to adjust an output of the resonant converting unit. The voltage detecting unit is configured to detect an output voltage of the resonant converting unit. The frequency modulation unit may adjust a lowest switching frequency of the control unit according to the detected output voltage so as to increase a gain of the resonant converting unit and an output stability of the resonant converting unit.

Abstract: A power supply apparatus includes an open loop power switcher, a power isolation transformer, a backlight driving circuit, and a power circuit. The open loop power switcher converts a direct current (DC) power into an alternating current (AC) input voltage. The power isolation transformer is coupled to the open loop power switcher and includes a primary-side winding, a first winding, and a second winding, wherein the first and second windings are disposed at the secondary-side of the power isolation transformer, and the first winding is employed for generating a first voltage signal according to the AC input voltage. The backlight driving circuit is employed for driving a backlight module according to the first voltage signal. The power circuit is employed for receiving a second voltage signal generated from the second winding according to the AC input voltage, in order to generate an output power signal.