Inventec Corp.

Chun-Hua Xia

Shih-Hao Liu

Li-Hong Huang

Li Zeng

Xiao-Ru Wu

Da-Wei Hu

A power converting device including a pulse width modulation circuit, a switch unit, a power output unit and a voltage start unit is provided. The pulse width modulation circuit increases a start voltage in a soft start mode and is operated under the start voltage to generate a pulse width modulation signal. The switch unit is for receiving an input voltage, and forming a charge path and a discharge path alternately according to the pulse width modulation signal. The power output unit converts the input voltage to a core voltage in accordance with the charge path and the discharge path. The voltage start unit is for detecting the start voltage, and for transmitting a control signal to interrupt the formation of the discharge path when the start voltage is smaller than the core voltage.

Soft start unit for a power converting device

A voltage regulating circuit including an error signal generator, a comparator, a switch unit, a low-pass filter and a modulating unit is provided. The error signal generator respectively receives a reference voltage signal and a feedback signal, and generates an error signal. The comparator respectively receives the error signal and a comparing signal, and generates a pulse width modulation signal. The switch unit regulates an input voltage signal to generate an output voltage signal according the pulse width modulation signal. The low-pass filter filters out the high frequency of the output signal and produces the feedback signal. The modulating unit is coupled to the low-pass filter and the error signal generator for regulating a transient voltage of the output voltage signal.

Voltage regulating circuit

A feedback and comparison apparatus applicable to a DC-DC voltage converter is provided. The feedback and comparison apparatus includes a comparator and a voltage feedback circuit. The voltage feedback circuit includes a first voltage dividing component and a second voltage dividing component. The comparator compares a feedback voltage with a first reference voltage, and outputs a control signal to the DC-DC voltage converter according to the comparing result. One end of the first voltage dividing component is coupled to an output voltage output by the DC-DC voltage converter and the other end of the first voltage dividing component is coupled to one end of the second voltage dividing component, for providing the feedback voltage. The other end of the second voltage dividing component is coupled to a second reference voltage. The present invention is applicable to a situation that the output voltage is smaller than the reference voltage.

Feedback and comparison apparatus and DC-DC voltage converter

A power factor correction circuit including a boost converter, a first capacitor, a first resistor, and a boost control unit is provided. The boost control unit includes a signal generator and a frequency controller. The boost converter transforms a rectified voltage to a correction voltage according to a pulse width modulation (PWM) signal. The first capacitor and the first resistor are coupled between an input terminal and a ground terminal of the boost converter. The boost control unit is adapted to generate the PWM signal, and adjust a duty cycle and a frequency of the PWM signal according to a current flowing through the first resistance, the rectified voltage and the correction voltage. Wherein, the signal generator is adapted to generate a ramp signal and adjust a slope of the ramp signal according to a charging current. The frequency controller adjusts the charging current according to the rectified voltage.

Power factor correction circuit and power supply apparatus thereof

A power measuring apparatus including a voltage transformer, a voltage-current measuring circuit, and an operation unit is provided. The voltage transformer converts an input voltage signal into an output voltage signal. The voltage-current measuring circuit includes an inductor, a first resistor, a first capacitor and a second capacitor. A first end of the first inductor herein receives the output voltage signal and a second end thereof generates a voltage feedback signal. The operation unit performs an operation on the voltage feedback signal and a terminal current signal between the first terminal and the second terminal of the first capacitor so as to calculate a power signal. In this way, the accuracy of thermal test is effectively increased by the presented invention.

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Shanghai, China

Chun-Hua Xia