Abstract: A synchronous rectification device is adapted to control a conversion circuit, where he conversion circuit includes: a primary side coil, configured to receive input power; and a secondary side coil, configured to generate inductive power in response to the input power. The synchronous rectification device includes: a first control circuit, configured to provide a first control signal to control the primary side coil; a secondary side switch, configured to generate an ON signal and an OFF signal according to the inductive power; an isolation coupling element; and a second control circuit. The isolation coupling element includes: a receiving side, configured to receive the first control signal; and a reaction side, configured to generate a coupling signal in response to the first control signal. The second control circuit outputs a second control signal according to the coupling signal, the ON signal, and the OFF signal to adjust the inductive power.

Abstract: A power conversion device includes a primary side rectifier, a main converter, a secondary side rectifier, a secondary side feedback controller, a PWM controller, and a driving compensator. The primary side rectifier is configured to generate a first voltage. The main converter includes a power transistor and is configured to adjust the first voltage to generate a second voltage according to a control signal. The secondary side rectifier is configured to generate an output voltage according to the second voltage. The secondary side feedback controller is configured to generate a feedback signal according to the output voltage. The PWM controller is configured to generate a PWM signal according to the feedback signal. The driving compensator includes a driving resistor circuit. The PWM signal outputs the control signal through the driving resistor circuit, and the driving compensator adjusts a resistance value of the driving resistor circuit according to the first voltage.

Abstract: A load detection circuit is applied to a power converter, and the power converter provides a switch switching frequency to control a switch output voltage. The load detection circuit includes a voltage adjustment unit, an integration unit, and a power switch. The voltage adjustment unit receives the switch output voltage provided from the power converter and adjusts the switch output voltage into an adjustment voltage. The integration unit is coupled to the voltage adjustment unit to receive the adjustment voltage and integrate the adjustment voltage to provide a control voltage. The power switch is coupled to the integration unit to receive the control voltage. When the switch switching frequency is increased to make the control voltage large enough to turn on the power switch, the load detection circuit detects that the power converter is changed from a no-loading condition to a loading condition.

Abstract: A power supply apparatus includes a main converter, an auxiliary winding switching circuit and a pulse width modulation controller. The main converter includes a transformer. The transformer includes a primary side winding, a secondary side winding and an auxiliary winding. The auxiliary winding includes a first winding and a second winding. According to a secondary side voltage, the first winding induces to generate a first voltage, and the second winding induces to generate a second voltage. The first voltage is greater than the second voltage. The auxiliary winding switching circuit sends the first voltage to the pulse width modulation controller when the first voltage is not greater than a predetermined voltage. The auxiliary winding switching circuit sends the second voltage to the pulse width modulation controller when the first voltage is greater than the predetermined voltage.

Abstract: A power supply apparatus includes a main converter, an auxiliary winding switching circuit and a pulse width modulation controller. The main converter includes a transformer. The transformer includes a primary side winding, a secondary side winding and an auxiliary winding. The auxiliary winding includes a first winding and a second winding. According to a secondary side voltage, the first winding induces to generate a first voltage, and the second winding induces to generate a second voltage. The first voltage is greater than the second voltage. The auxiliary winding switching circuit sends the first voltage to the pulse width modulation controller when the first voltage is not greater than a predetermined voltage. The auxiliary winding switching circuit sends the second voltage to the pulse width modulation controller when the first voltage is greater than the predetermined voltage.

Abstract: A power supply apparatus includes a main converter, a voltage superposition circuit, a voltage detection circuit and a pulse width modulation controller. The voltage superposition circuit is electrically connected to the main converter. The voltage detection circuit is electrically connected to the main converter and the voltage superposition circuit. The pulse width modulation controller is electrically connected to the main converter and the voltage detection circuit. The main converter includes a sensing resistor. The voltage detection circuit detects a sensing voltage of the sensing resistor. The voltage superposition circuit supplies a superposition voltage to the voltage detection circuit when an output voltage of the power supply apparatus is less than a predetermined output voltage, and then the voltage detection circuit sends the sensing voltage and the superposition voltage to the pulse width modulation controller.