A DC/DC converter and a voltage gain switching method and system. A first resonance unit of the DC/DC converter includes a first terminal and a second terminal connected to a second capacitor unit, and a third terminal and a fourth terminal connected to a first capacitor unit. A second resonance unit of the DC/DC converter includes a first terminal connected to a second terminal of the second capacitor unit, and a second terminal of the second resonance unit connected to a first input/output terminal of the DC/DC converter, a third terminal connected to the ground terminal of the DC/DC converter, and a fourth terminal connected to a first voltage gain changeover switch. The DC/DC converter can improve voltage gain switching efficiency.

A resonant core power supply includes a core with excitation, resonant, and load windings where the resonant winding is coupled to a tank circuit and a controller manipulates the phase, amplitude and waveform of an excitation signal applied to the excitation winding.

A power conversion circuit is provided. According to the topologies of power conversion circuits and the corresponding control manners of the present disclosure, the output voltage is greatly reduced relative to the input voltage, and thus the function of voltage reduction is achieved. Moreover, a voltage-second product of the time and the voltage across the first output inductor and a voltage-second product of the time and the voltage across the second output inductor are both greatly reduced. Accordingly, the inductance, volume and loss of the first output inductor and the second output inductor are greatly reduced. Therefore, the voltage regulation module may receive the low output voltage outputted by the power conversion circuit, thereby reducing the overall volume of the voltage regulation module and increasing the power conversion density and conversion efficiency of the voltage regulation module.

A switched capacitor voltage converter circuit includes: a switched capacitor converter and a control circuit. In a charging process of a resonant operation mode, the switches in the switched capacitor converter operate to form a series connection of at least one capacitor and an inductor between a first voltage and a second voltage, as a charging path. In a discharging process of the resonant operation mode, the switches operate to form a series connection of each capacitor and the inductor between the second voltage and a ground level, thus forming plural discharging paths simultaneously or sequentially. In an inductor switching mode, the switches operate to couple one end of the inductor to the first voltage or the ground level alternatingly. The control circuit decides to operate in the resonant operation mode or the inductor switching mode according to the first voltage, thereby maintaining the second voltage within a predetermined range.

A power supply adjustment method may include: providing a pulse-width modulation (PWM) signal, a duty cycle of the PWM signal being preset to a fixed value; performing PWM processing on an input signal by using the PWM signal to obtain a first modulation signal;

performing first filtering processing on the first modulation signal to obtain a second modulation signal; and performing linear adjustment processing on the second modulation signal to output a target signal. According to the power supply adjustment method, the power supply apparatus, the portable component, and the magnetic resonance device provided in the present disclosure, interference of noise generated by PWM on the portable component can be reduced, thereby reducing requirements for a shielding component, further reducing a weight of the portable component in the magnetic resonance device and improving portability.

According to one aspect of the present disclosed subject matter, a receiver inductively powered by a transmitter for powering a load, the receiver comprising: a resonance circuit capable of tuning its resonance frequency for coupling with the transmitter and generate AC voltage; a power supply section configured to rectify the AC voltage and adjust a DC current and a DC voltage to the load; and a control and communication section designed to set parameters for the receiver and communicate operation points (OP) to the transmitter, wherein the parameters and the OP derived from determining a minimal power loss of the receiver.

A switching power supply apparatus includes a switching circuit, a resonance circuit, a rectifying circuit, and a control circuit. The switching circuit includes switching elements connected in series between input terminals of a source. The resonance circuit includes an excitation inductor of a primary winding of a transformer, a resonance inductor connected in series with the excitation inductor, and a variable resonance capacitor which is connected in series with the excitation inductor and whose electrostatic capacity changes according to a control voltage. The control circuit generates, on the basis of a feedback voltage, switching signals in which frequency diffusion is given to a switching frequency and the control voltage and outputs the switching signals and the control voltage to simultaneously change the switching frequency and the electrostatic capacity of the variable resonance capacitor.

A resonant switching power converter includes: plural capacitors; plural switches; at least one charging inductor; at least one discharging inductor; a controller which generates a charging operation signal and at least one discharging operation signal; and at least one zero current detection circuit which detects a charging resonant current flowing through the charging inductor in a charging process and/or detect a discharging resonant current flowing through the discharging inductor in a discharging process. When detecting that a level of the charging resonant current or a level of the discharging resonant current is zero, the zero current detection circuit generates at least one zero current detection signal which is sent to the controller. The controller determines start time points and end time points of the charging process and the discharging process according to the zero current detection signal. There can be plural discharging processes.

A power transmission device includes a transmission coil that supplies power to a power reception device, a power supply circuit that converts DC power supplied from a DC power source via a plurality of switching elements connected in a full bridge shape or a half bridge shape between DC power sources and the transmission coil into AC power and supplies the AC power to the transmission coil, a phase adjustment circuit having an LC series circuit connected in parallel with the transmission coil and a switching element connected in series with the LC series circuit, and a control circuit that controls switching on and off of the switching element of the phase adjustment circuit in accordance with a measured value of an amount of current when any of the plurality of switching elements of the power supply circuit is turned off by a current detection circuit.

A resonant inverter is provided that includes a first switch and a second switch alternately turned on and off, a first inverter including the first switch and a first resonant circuit including a first coil and a first capacitor, and a second inverter including the second switch and a second resonant circuit including a second coil and a second capacitor. The first coil, the second coil, and a third capacitor constitute a third resonant circuit.