An example electronic device is described. The electronic device includes a voltage converter and a switching circuit. The switching circuit includes a first switch to couple a first energy-absorbing circuit to the voltage converter to decrease a voltage spike generated during operation of the voltage converter when a value of an output current of the voltage converter is in a first current range. The switching circuit further includes a second switch to couple a second energy-absorbing circuit to the voltage converter to decrease the voltage spike, when the value of the output current is in a second current range.

Disclosed herein is an improved flyback converter that separates the magnetic components of the converter into a transformer and a separate, discrete energy storage inductor. This arrangement can improve the operating efficiency of the converter by reducing the commutation losses as compared to a conventional flyback converter. The magnetic components may be constructed on separate magnetic cores or may be constructed on magnetic cores having at least one common element, thereby allowing for at least partial magnetic flux cancellation in a portion of the core, reducing core losses.

An automotive vehicle includes an electric machine, a traction battery, and a power converter. The power converter transfers power between the electric machine and traction battery. The power convert includes a switch that defines a portion of a phase leg, a gate driver circuit that provides provide power to a gate of the switch, and a clamping circuit. The clamping circuit includes a clamping switch that, responsive to the gate driver circuit being de-energized and a voltage of the gate exceeding a predetermined threshold value, conducts current from the gate to dissipate the voltage and clamp the gate to an emitter of the switch.

This application discloses a power supply guarantee system and method. The power supply guarantee system is applied to a battery management system. The power supply guarantee system includes: a main control module, configured to send a received wake-up time to a timing device; a high voltage power module, configured to power the timing device according to electrical energy in a high voltage battery pack; the timing device, configured to set a wake-up clock according to the wake-up time, start timing when the BMS enters sleep, and send a discharge instruction to the high voltage battery pack when the timing reaches the wake-up time; and a power conversion module, configured to convert high voltage electrical energy into low voltage electrical energy, and use the low voltage electrical energy to power the BMS, where the high voltage electrical energy is output by the high voltage battery pack according to the discharge instruction.

A flyback power-converting device includes a transformer circuit, a clamp damping circuit, a first switch, a voltage-reducing circuit and a second switch. The clamp damping circuit and the first switch are coupled to the transformer circuit. The voltage-reducing circuit and the second switch are coupled in series between the clamp damping circuit and the transformer circuit. Through switching of the first switch, the transformer circuit converts an input power to generate a first converted voltage and to enable the clamp damping circuit to store an inductive energy. In addition, when the second switch is turned on, the clamp damping circuit releases the inductive energy to the transformer circuit via the voltage-reducing circuit, so that the transformer circuit generates a second converted voltage according to the inductive energy.

A method is provided for operating a resonant power conversion apparatus The method may include charging a capacitor connected to a power source in parallel, and determining a discharge time point and a discharge period of a discharge circuit, where the discharge circuit includes a resistor and a switch connected in series and is connected to the capacitor in parallel. The method may also include outputting, by a switch control circuit, a switch control signal by determining the switch control signal based on the discharge time point and the discharge period, and discharging the charged capacitor through the resistor based on the switch control signal applied to the switch. A resonant power conversion apparatus for performing the above-described method is provided.

A power factor correction circuit includes an input power source, a first bridge arm, a second bridge arm, an output capacitor and an active clamp unit. The first bridge arm includes a first switch and a second switch in series. The second bridge arm includes a third switch and a fourth switch in series. The active clamp unit includes a second inductor, a clamp capacitor and a fifth switch. The power factor correction circuit may realize the ZVS function of the first switch and the second switch by the collaboration of the active clamp unit and the conduction/non-conducting state of the first switch, the second switch, the third switch and the fourth switch.

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.

A self-driven active clamp circuit applied to a flyback converter having a transformer and a switch has a clamp switch and a resistor. The clamp switch is connected between a first capacitor and a second capacitor in series. Another terminal of the first capacitor is connected to a first terminal of a primary-side winding of the transformer. Another terminal of the second capacitor is connected to a second terminal of the primary-side winding of the transformer and the switch of the flyback converter. A terminal of the resistor is connected to a control terminal of the clamp switch. Another terminal of the resistor is connected to the second terminal of the primary-side winding of the transformer and the switch of the flyback converter.

A multi-mode hybrid control DC-DC converting circuit has a switching power converter and a microcontroller. The switching power converter has a transformer and a switching switch. The switching switch is connected to a primary-side winding of the transformer in series. The microcontroller is connected to the switching power converter and a control terminal of the switching switch. The microcontroller sets multiple thresholds according to an input voltage of the switching power converter, and determines whether a feedback voltage of the switching power converter is higher or lower than each one of the thresholds to perform a variable-frequency mode, a constant-frequency mode, or a pulse-skipping mode. The microcontroller outputs a driving signal to the switching switch and correspondingly adjusts a frequency of the driving signal according to the variable-frequency mode, the constant-frequency mode, or the pulse-skipping mode which is performed.