Asian Power Devices Inc.

Yeu-Torng Yau

Tsung-Liang Hung

Ya-Lun Ouyang

A network communication power supply with digital signal isolation includes a transformer, a transformer drive circuit, a rectifier, and a modulation signal duty cycle detection circuit. The transformer has a primary side and a secondary side. The transformer drive circuit is coupled to the primary side, and receives a digital signal input. The transformer drive circuit converts the digital signal input into a drive signal with a duty cycle corresponding to a logic level of the digital signal input according to the logic level. The digital signal input includes a power content. The rectifier is coupled to the secondary side and converts the power content to provide a power source. The modulation signal duty cycle detection circuit is coupled to the rectifier and supplied power by the power source, and provides a digital signal output with a high or low level according to the duty cycle.

Network communication power supply with digital signal isolation

A conversion apparatus with overload control includes a primary conversion circuit, a resonant conversion circuit, and a control unit. The control unit controls a voltage value of a DC power source outputted from the primary conversion circuit according to a current signal of an output current of the resonant conversion circuit. When the control unit realizes that the output current exceeds a rated current according to the current signal, the control unit steps up the voltage value of the DC power source.

Conversion apparatus with overload control and overload control method for the same

A hysteresis voltage detection circuit includes a voltage stabilizing unit, a first power switch, a first voltage dividing resister, a second voltage dividing resister, a third voltage dividing resistor and a second power switch. The voltage stabilizing unit is coupled to an adjustable voltage source. When both the first power switch and the second power switch are turned on, the first voltage dividing resistor, the second voltage dividing resistor, and the third voltage dividing resistor divide the adjustable voltage source. When both the first power switch and the second power switch are turned off, the first voltage dividing resistor and the second voltage dividing resistor divide the adjustable voltage source.

Hysteresis voltage detection circuit

A power conversion apparatus with oscillation reduction control supplies power to a load through an output end. The power conversion apparatus includes a transformer, a power switch, a control module, and an oscillation reduction control module. A primary side of the transformer receives an input voltage, and a secondary side of the transformer is coupled to the output end. The power switch is coupled to the primary side. The control module is coupled to the power switch, controls the power switch continuously turning on and turning off, and converts the input voltage into an output voltage. When the oscillation reduction control module detects a resonance voltage through the secondary side, the oscillation reduction control module performs an oscillation reduction operation to the resonance voltage to reduce an amplitude of the resonance voltage by a damper.

Power conversion apparatus with oscillation reduction control, oscillation reduction control module, and method of operating the same

A conversion apparatus with oscillation reduction control includes a conversion circuit and an oscillation reduction control circuit. The conversion circuit includes a transformer, a rectifying circuit, and a first switch. The oscillation reduction control circuit stores a leakage inductance energy of the transformer when the first switch is turned off, and the oscillation reduction control provides the leakage inductance energy to a primary-side winding of the transformer when the first switch is turned on.

Conversion apparatus with oscillation reduction control and method of operating the same

A power factor correction circuit with burst setting includes a conversion circuit, a control unit, and a burst setting circuit. The burst setting circuit respectively sets at least one burst period when an input power source is at a rising edge of a positive half cycle, a falling edge of the positive half cycle, the rising edge of a negative half cycle, and the falling edge of the negative half cycle, and provides a burst setting signal corresponding to the at least one burst period to the control unit so that the control unit limits the conversion circuit to perform a burst operation during the at least one burst period.

Power factor correction circuit with burst setting and method of operating the same

A bridgeless step-up and step-down AC-to-DC converter is used to convert an AC input power source into a DC output power source. The converter includes a first circuit, a second circuit, a third circuit, a third diode, and a fourth diode. The first circuit has a first end, a second send, and a third end; the first end is coupled to the AC input power source, the second end is coupled to a ground end, and the third end is coupled to the DC output power source. The second circuit has a first end, a second end, and a third end; the first end is coupled to the AC input power source, the second end is coupled to the ground end, and the third end is coupled to the DC output power source.

Bridgeless step-up and step-down AC-to-DC converter

A dual-mode active clamp flyback converter includes a transformer circuit, a clamping energy storage circuit, and a main switch circuit. The transformer circuit is coupled to a load, and the transformer circuit includes an auxiliary winding. The clamping energy storage circuit is coupled to the transformer circuit. If the load as a heavy loading, the clamping energy storage circuit is turned on. If the load as a light loading, the clamping energy storage circuit is turned off. The main switch circuit is coupled to the transformer circuit. When the main switch circuit is turned on, the auxiliary winding releases energy to a primary-side winding of the transformer circuit.

Dual-mode active clamp flyback converter

A method of controlling a resolution of digital pulse width modulation is applied to a digital pulse width modulation generator. The method is to divide a value of a first duty clock by a value of a first pulse width modulation period clock to generate a first resolution. And then, if it is confirmed that a modulation command has been received, a second resolution is generated, and if it is confirmed that the modulation command is not received, a third resolution is generated. The second resolution is greater than the first resolution, and the second resolution is less than the third resolution.

Method of controlling resolution of digital pulse width modulation

An LLC converter includes a switch module, a transformer, an output circuit, a resonant circuit and a safety capacitor. The switch module is connected between an input voltage and a ground. The transformer has a primary side winding and at least one secondary side winding. The output circuit is connected between the at least one secondary side winding and a load. The resonant circuit is coupled between the primary side winding and the switch module and includes at least one leakage inductor. The safety capacitor is connected between the at least one leakage inductor and the switch module.

LLC resonant converter

A flicker-free LED driving apparatus and voltage regulating method thereof are disclosed. The apparatus includes a power conversion circuit receiving an AC electricity and then generating an output voltage with a ripple component for an LED string; a feedback circuit electrically connected to the power conversion circuit and generating a feedback signal with varying duty cycle according to operation states of the LED string; a power conversion circuit including, a controller receiving the feedback signal turns on or off a switching device thereof according to the feedback signal; and a linear voltage-regulating circuit electrically connected to the power conversion circuit, the feedback circuit, and the LED string. and configured to regulate the output voltage in accordance with a voltage difference between the output voltage and a voltage across the LED string.

Flicker-free LED driving apparatus and voltage regulating method thereof

An electronic device is provided. The electronic device integrates an enable function and an over-temperature protection function (OTP) on the same line, thereby reducing the PCB layout between a microcontroller and a mainboard circuit, and further reducing the circuit complexity and cost. In addition, the negative temperature coefficient (NTC) thermistor in the electronic device is also directly coupled to a circuit pin used for the enable function of the microcontroller to serve as an over-temperature protection application. Therefore, even if the microcontroller fails, the electronic device may still use the hardware circuit structure to automatically achieve the over-temperature protection function.

Electronic device

A passive coupled-inductor soft-switching circuit of a power factor corrector is provided. The passive coupled-inductor soft-switching circuit includes a power input terminal, a first inductor, a first diode, a power output terminal, a power switch and a buffer circuit. The first inductor has a first terminal and a second terminal, wherein the first terminal of the first inductor is electrically coupled with the power input terminal. The first diode has a positive terminal and a negative terminal, wherein the positive terminal of the first diode is electrically coupled with the second terminal of the first inductor. The power output terminal is electrically coupled with the negative terminal of the first diode. The buffer circuit is electrically coupled with the power switch. By using the buffer circuit, the voltage and current have phase interlacing shifts and thereby reducing the switching loss.

Passive coupled-inductor soft-switching circuit of power factor correctors

A parallel resonant converter circuit with current-equalization function includes a power input terminal, a power output terminal, an output capacitor, first and second resonant converters and a third transformer. The first resonant converter is electrically coupled between the power input terminal and the output capacitor/power output terminal. The first resonant converter includes a first transformer. The second resonant converter is electrically coupled between the power input terminal and the output capacitor. The first resonant converter and the second resonant converter are coupled in parallel. The second resonant converter includes a second transformer. The third transformer includes a first coil winding set and a second coil winding set. The first coil winding set is electrically coupled between the power input terminal and the first transformer in series. The second coil winding set is electrically coupled between the power input terminal and the second transformer in series.

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Taoyuan, Taiwan

Yeu-Torng Yau