Abstract: A boost converter includes a first inductor, a power switch element, an output stage circuit, a controller, a resonant circuit, and a discharging circuit. The first inductor receives an input voltage. The power switch element includes a parasitic capacitor. The output stage circuit includes a first resistor. The output stage circuit generates an output voltage. The controller detects the resistive voltage of the first resistor, and generates a clock voltage, a first control voltage, and a second control voltage according to the resistive voltage. The resonant circuit is coupled to the first inductor, and is selectively enabled or disabled according to the first control voltage. When the resonant circuit is enabled, the resonant circuit resonates with the first inductor and the parasitic capacitor, so as to fine-tune an inductive current flowing through the first inductor.

Abstract: A boost converter includes a voltage divider circuit, a first comparator, a tunable inductive element, a power switch element, a second comparator, an output stage circuit, and a controller. The voltage divider circuit receives an input voltage. The tunable inductive element is coupled to the voltage divider circuit. The total inductance of the tunable inductive element is controlled by the first comparator. The output stage circuit is coupled to the tunable inductive element and the power switch element. The output stage circuit includes a tunable resistive element. The total resistance of the tunable resistive element is controlled by the second comparator. When the boost converter operates in a first mode, an output voltage of the output stage circuit has a relatively high voltage level. When the boost converter operates in a second mode, the output voltage of the output stage circuit has a relatively low voltage level.

Abstract: A power supply device includes an energy tank, a discharging and starting circuit, a fuse, a bridge rectifier, a transformer, a power switch element, an output stage circuit, and a controller. The energy tank includes an NTC (Negative Temperature Coefficient) thermistor. The energy tank absorbs a burst high voltage, and converts the burst high voltage into thermal energy. The discharging and starting circuit is coupled to the energy tank. The discharging and starting circuit includes a bypass path. When the resistance of the NTC thermistor is smaller than a threshold value, the bypass path is enabled, such that the energy tank is coupled through the bypass path to a ground and a ground voltage. The bridge rectifier is coupled through the fuse to the energy tank. The discharging and starting circuit is selectively configured to enable the controller.

Abstract: A power supply device includes an energy tank, a discharging and starting circuit, a fuse, a bridge rectifier, a transformer, a power switch element, an output stage circuit, and a controller. The energy tank includes an NTC (Negative Temperature Coefficient) thermistor. The energy tank absorbs a burst high voltage, and converts the burst high voltage into thermal energy. The discharging and starting circuit is coupled to the energy tank. The discharging and starting circuit includes a bypass path. When the resistance of the NTC thermistor is smaller than a threshold value, the bypass path is enabled, such that the energy tank is coupled through the bypass path to a ground and a ground voltage. The bridge rectifier is coupled through the fuse to the energy tank. The discharging and starting circuit is selectively configured to enable the controller.

Abstract: A boost converter includes a first inductor, a first switch element, a second switch element, a tuning circuit, and an output stage circuit. A first parasitic capacitor is built in the first switch element. The first switch element selectively couples the first inductor to a ground voltage according to a first control voltage. A second parasitic capacitor is built in the second switch element. The second switch element selectively couples the first inductor to the output stage circuit according to a second control voltage. The tuning circuit includes a second inductor, a third inductor, and a discharge path. The first parasitic capacitor resonates with the second inductor and is coupled through the discharge path to the ground voltage, or the second parasitic capacitor resonates with the third inductor and is coupled through the discharge path to the ground voltage.

Abstract: A boost converter includes a first inductor, a power switch element, a tuning circuit, and an output stage circuit. The first inductor is configured to receive an input voltage. A parasitic capacitor is built in the power switch element. The power switch element selectively couples the first inductor to a ground voltage according to a clock voltage. The output stage circuit is configured to generate an output voltage. The tuning circuit includes a second inductor, a third inductor, and a current-limiting path. The second inductor is coupled to the first inductor and the power switch element. The third inductor is coupled through the current-limiting path to the output stage circuit. The first inductor, the second inductor, and the third inductor are mutually coupled to each other, so as to form an equivalent transformer.

Abstract: A power supply apparatus including a rectifier circuit, an energy storage circuit, a power conversion circuit, a detection circuit, an energy supplement circuit, and a control circuit is provided. The rectifier circuit rectifies an AC voltage and provides a DC voltage. The energy storage circuit and the energy supplement circuit store electrical energy according to the DC voltage. The power conversion circuit converts the DC voltage into an output voltage. The detection circuit detects a voltage amplitude of the AC voltage according to the DC voltage and generates a detection signal group accordingly. The control circuit is coupled to the detection circuit to receive the detection signal group. When the control circuit determines that the voltage amplitude of the AC voltage is less than or equal to a first threshold according to the detection signal group, the control circuit instructs the energy supplement circuit to charge the energy storage circuit.

Abstract: A power conversion apparatus including a transformer, a power switch, a pulse width modulation (PWM) signal generator, an energy storage element, and a power circuit is provided. A primary winding of the transformer receives an input voltage from an external power source. An auxiliary winding of the transformer provides an auxiliary voltage. The power switch is coupled to the primary winding. The PWM signal generator generates a PWM signal to control on and off the power switch. The energy storage element is coupled to a power terminal of the PWM signal generator. The power circuit supplies power to the PWM signal generator and charges the energy storage element according to the auxiliary voltage. When a voltage of the energy storage element is greater than or equal to a threshold voltage, the power circuit stores backup power according to the auxiliary voltage.

Abstract: A boost converter includes a first inductor, a power switch element, an output stage circuit, a controller, a resonant circuit, and a discharging circuit. The first inductor receives an input voltage. The power switch element includes a parasitic capacitor. The output stage circuit includes a first resistor. The output stage circuit generates an output voltage. The controller detects the resistive voltage of the first resistor, and generates a clock voltage, a first control voltage, and a second control voltage according to the resistive voltage. The resonant circuit is coupled to the first inductor, and is selectively enabled or disabled according to the first control voltage. When the resonant circuit is enabled, the resonant circuit resonates with the first inductor and the parasitic capacitor, so as to fine-tune an inductive current flowing through the first inductor.

Abstract: An LED driving circuit includes a transformer circuit, a voltage supply circuit, a voltage-stabilizing circuit and a ripple compensation circuit. The transformer circuit is configured to convert an input voltage into a ripple output voltage. The voltage supply circuit is configured to provide a driving voltage associated with the maximum value of the ripple output voltage. The voltage-stabilizing circuit is configured to provide a first pulse DC voltage associated with the variation of the ripple output voltage. The ripple compensation circuit is configured to provide a second pulse DC voltage associated with the value of the input voltage, provide a compensation voltage according to the first pulse DC voltage, the second pulse DC voltage and the driving voltage, and provide a pure DC output voltage by superposing the compensation voltage on the ripple output voltage.

Abstract: A power conversion apparatus including a transformer, a power switch, a pulse width modulation (PWM) signal generator, an energy storage element, and a power circuit is provided. A primary winding of the transformer receives an input voltage from an external power source. An auxiliary winding of the transformer provides an auxiliary voltage. The power switch is coupled to the primary winding. The PWM signal generator generates a PWM signal to control on and off the power switch. The energy storage element is coupled to a power terminal of the PWM signal generator. The power circuit supplies power to the PWM signal generator and charges the energy storage element according to the auxiliary voltage. When a voltage of the energy storage element is greater than or equal to a threshold voltage, the power circuit stores backup power according to the auxiliary voltage.

Abstract: An accelerating discharge device includes a first parallel inductive element, a second parallel inductive element, a first capacitor, a noise suppression element, a one-way element, a first discharge circuit, a second discharge circuit, a first switch element, and a second switch element. The first parallel inductive element generates a first control voltage according to a first input voltage. The second parallel inductive element generates a second control voltage according to a second input voltage. The first switch element selectively couples the first parallel inductive element through the second discharge circuit to a ground according to the first control voltage. The second switch element selectively couples the second parallel inductive element through the second discharge circuit to the ground according to the second control voltage.

Abstract: A power conversion device is provided for supplying power to an electronic device. The power conversion device includes a power supply connector, a voltage conversion circuit, a switch circuit and a detection circuit. The power supply connector is configured to couple with the electronic device. The voltage conversion circuit is configured to provide a suitable voltage level for the electronic device. The switch circuit is coupled between the voltage conversion circuit and the power supply connector. When the power supply connector is coupled with the electronic device and a ground pin of the power supply connector is fully shielded, the detection circuit configures the switch circuit to be conducted for supplying power to the electronic device.

Abstract: A power supply device includes a switch circuit, a resonant circuit, a first transformer, an output rectifier, a feedback circuit, and a controller. The switch circuit generates a switch voltage according to an input voltage, a first clock voltage, and a second clock voltage. The resonant circuit includes a variable capacitor and a variable inductor. The resonant circuit generates a resonant voltage according to the switch voltage, a first control voltage, and a second control voltage. The first transformer generates a transformation voltage according to the resonant voltage. The output rectifier generates an output voltage according to the transformation voltage. The feedback circuit and the controller detect a sensing voltage relative to the output rectifier. The feedback circuit determines the first control voltage according to the sensing voltage. The controller determines the second control voltage according to the sensing voltage.

Abstract: A power supply apparatus including a rectifier circuit, an energy storage circuit, a power conversion circuit, a detection circuit, an energy supplement circuit, and a control circuit is provided. The rectifier circuit rectifies an AC voltage and provides a DC voltage. The energy storage circuit and the energy supplement circuit store electrical energy according to the DC voltage. The power conversion circuit converts the DC voltage into an output voltage. The detection circuit detects a voltage amplitude of the AC voltage according to the DC voltage and generates a detection signal group accordingly. The control circuit is coupled to the detection circuit to receive the detection signal group. When the control circuit determines that the voltage amplitude of the AC voltage is less than or equal to a first threshold according to the detection signal group, the control circuit instructs the energy supplement circuit to charge the energy storage circuit.

Abstract: A power conversion apparatus including a transformer, a power switch, a pulse width modulation (PWM) signal generator, an energy storage element, and a power circuit is provided. A primary winding of the transformer receives an input voltage from an external power source. An auxiliary winding of the transformer provides an auxiliary voltage. The power switch is coupled to the primary winding. The PWM signal generator generates a PWM signal to control on and off the power switch. The energy storage element is coupled to a power terminal of the PWM signal generator. The power circuit supplies power to the PWM signal generator and charges the energy storage element according to the auxiliary voltage. When a voltage of the energy storage element is greater than or equal to a threshold voltage, the power circuit stores backup power according to the auxiliary voltage.

Abstract: A power supply apparatus including a protection circuit and a power conversion circuit is provided. The protection circuit includes a control circuit, an auxiliary capacitor, and a switching circuit. The control circuit receives an AC voltage from an AC power source and generates a pulsating voltage and a control signal accordingly. The auxiliary capacitor receives the pulsating voltage and provides a first voltage accordingly. The switching circuit is coupled to the auxiliary capacitor to receive the first voltage and coupled to the control circuit to receive the control signal. The switching circuit transmits the first voltage to the power conversion circuit in response to the control signal. The power conversion circuit converts the first voltage to an output voltage. When the switching circuit is switched to an on state in response to the control signal, the auxiliary capacitor reduces an input inrush current from the AC power source.

Abstract: A power supply apparatus including a PWM signal generating circuit, a power conversion circuit, a voltage dividing circuit, a capacitor circuit, and a feedback compensation circuit is provided. The PWM signal generating circuit generates and modulates a PWM signal according to a feedback signal. The power conversion circuit converts an input voltage into an output voltage according to the PWM signal. The voltage dividing circuit divides the output voltage and generates a first voltage to a node. The capacitor circuit generates a second voltage to the node according to the output voltage in response to a voltage change of the output voltage. The feedback compensation circuit generates the feedback signal based on the first voltage and a reference voltage before the output voltage is ready. The feedback compensation circuit generates the feedback signal based on the second voltage and the reference voltage after the output voltage is ready.

Abstract: A voltage compensation driving circuit is provided. The voltage compensation driving circuit converts input power into output power and auxiliary power. The voltage compensation driving circuit provides a boost control signal according to an output current of the output power, and the boost control signal has a duty cycle corresponding to the output current. The voltage compensation driving circuit boosts the auxiliary power by the boost control signal to generate a compensation voltage and transmits the compensation voltage to a light emitting device string via a boost resistor, so as to linearly control a brightness of the light emitting device string.

Abstract: A power supply device includes a voltage dividing circuit, a first transformer, a comparator, a second transformer, and an output stage circuit. The voltage dividing circuit generates a reference voltage according to an input voltage. The first transformer generates a transformation voltage and a feedback voltage according to the input voltage. The comparator compares the feedback voltage with the reference voltage to generate a comparison voltage. The second transformer generates a control voltage according to the comparison voltage. The output stage circuit selectively generates an output voltage according to the transformation voltage and the control voltage. If the RMS (Root-Mean-Square) value of the input voltage is higher than or equal to a threshold voltage, the output stage circuit will continuously output the output voltage. If the RMS value of the input voltage is lower than the threshold voltage, the output stage circuit will stop outputting the output voltage.