Abstract: A control circuit for a synchronous rectification circuit, a LLC resonant converter and a control method. The control circuit has a first comparing circuit, a second comparing circuit, a blanking circuit, a first logic circuit and a second logic circuit. The blanking circuit is configured to provide a first blanking signal and a second blanking signal to avoid one or more repeated conduction of a first synchronous rectifier and a second synchronous rectifier respectively, and the first blanking signal and the second blanking signal are logic complementary.

Abstract: A switching power supply apparatus includes: a dead time circuit that receives an output control signal and generates dead time signal to specify a time width when both first and second switching elements are turned OFF; an output signal generation circuit that generates first and second output signals which specify the ON time of the first and second switching elements respectively in accordance with the output control signal and the dead time signal; and a dead time adjustment circuit that adjusts the turn ON timings of the first and second switching elements by changing the time width of the dead time signal in accordance with the change of voltage of the DC input power or the change of the output voltage of the capacitor.

Abstract: Included are a switching power supply device main body, and a frequency control circuit that controls the switching frequency of a switching element in accordance with a feedback signal in accordance with the output voltage of the switching power supply device main body. The frequency control circuit is divided into a frequency control region wherein the amount of the feedback signal is greater than a predetermined boundary value and a frequency control region wherein the amount is less, linear frequency control whereby the switching frequency of the switching element is caused to change linearly in accordance with the feedback signal is executed in the frequency control region wherein the feedback amount is less, and linear cycle control whereby the switching cycle of the switching element is caused to change linearly in accordance with the feedback signal is executed in the frequency control region wherein the feedback amount is greater.

Abstract: There is provided a power supply device, including an insulating direct current to direct current (DC/DC) converter unit including a primary side winding and a secondary side winding inductively coupled to the primary side winding and inducing a voltage in the secondary side winding in a first direction or a second direction, and a boost unit including a first boost converter boosting the voltage induced in the secondary side winding, in a first mode in which the voltage is induced in the secondary side winding in the first direction, and a second boost converter boosting the voltage induced in the secondary side winding, in a second mode in which the voltage is induced in the secondary side winding in the second direction.

Abstract: A resonant converter, a power supply and a power controlling method thereof are provided. The power supply includes a resonant converter which includes a square wave generator configured to alternately turn on and off first and second switches according to a frequency to generate a square wave, a resonant wave generator configured to generate a resonant wave corresponding to the square wave and a rectifier configured to output a voltage corresponding to the resonant wave; and a controller configured to control a frequency modulation of the resonant converter, wherein the controller includes a variable switching circuit configured to increase the frequency of the resonant converter in response to the resonant converter entering a capacitive mode.

Abstract: LLC power converters are disclosed that operate in the soft switching region and are defined by a range of frequencies within which soft switching occurs. The LLC power converters include an LLC tank circuit in which the values of the inductors and the capacitors are scaled by a frequency scaling factor and a power scaling factor based on selected design parameters for the LLC power converter. The switching frequency of the disclosed LLC power converters can be varied by an output voltage to switching frequency controller.

Abstract: A LLC bidirectional resonant converter comprising: a resonant tank, a first switching circuit connected to the resonant tank via first power conduits, a second switching circuit connected to the resonant tank via second power conduits, a switching element, and at least one switchable inductive element which is arranged by the switching element to be in parallel across the second power conduits when operating in a first mode of operation and arranged by the switching element to be in parallel across the first power conduits when operating in a second mode of operation.

Abstract: A switching regulator related to aspects of the invention can include an auxiliary winding for monitoring the voltage across the primary winding of a transformer, a differentiation detecting circuit that detects the timing of reversal start or reversal end of the signal detected by the auxiliary winding and a dead time adjusting circuit that receives a signal to trigger turn OFF of a first switch or a second switch and, after passing a predetermined delay time from the detection of the signal, generates a signal to trigger turn ON of the first switch or the second switch. The differentiation detecting circuit can confirm current transfer between body diodes. The dead time adjusting circuit can adjust a dead time to deliver the signal after a predetermined time from the confirmation of the current transfer. In some aspects of the invention, occurrence of hard switching and short-circuit current can be suppressed.

Abstract: An apparatus and system for power conversion. In one embodiment, the apparatus comprises a transformer having a primary winding and a plurality of secondary windings; and a cyclo-converter comprising a plurality of switch pairs for converting an alternating current to an AC current, wherein each switch pair in the plurality of switch pairs (i) is coupled between two lines of an AC output and (ii) has a different secondary winding of the plurality of secondary windings coupled between its switches.

Abstract: In a switching power supply apparatus, a resonant capacitor and an inductor are connected in series between a primary winding in a transformer and a second switching element. A first rectifier smoothing circuit including a diode and a capacitor rectifies and smoothes a voltage occurring at a first secondary winding in the transformer during an on period of a first switching element to extract a first output voltage. A second rectifier smoothing circuit including a diode and a capacitor rectifies and smoothes a voltage occurring at a second secondary winding in the transformer during an on period of the second switching element to extract a second output voltage. A control circuit controls an on time of the first switching element and an on time of the second switching element on the basis of the first output voltage and the second output voltage.

Abstract: A new and useful method and inductive circuit is provided that provides a resonant transition control that involves shorting the winding of an inductor or transformer to delay the natural ringing transition. The present invention provides for controlling the natural ring of an inductive circuit has a choke that stores and releases energy, a switch device having a closed state in which it causes the choke to store energy and another switch device having a closed state in which it causes the choke to release energy. The inductive circuit is configured with parasitic capacitance that would normally produce natural ringing when energy in the choke has been substantially released. The invention is characterized in that it provides for shorting the choke to trap and hold current and pause the natural ringing until power is directed to the inductive circuit to release shorting of the choke and initiate storage of energy in the choke.

Abstract: This disclosure relates to a switching power supply with regulated voltage suppression to reduce transformer audio noise. A switched mode power supply (SMPS) may supply power at different levels according to output loads. A switching frequency of the SMPS may be adjusted according to the output load. The switching may be subject to a ringing suppression time, a maximum on time, and a maximum switching period. By controlling the switching frequency subject to these quantities, the audible noise of an SMPS may be reduced or eliminated.

Abstract: One embodiment relates to an LLC resonant power converter system. The system includes a transformer comprising a primary inductor and a secondary inductor and a switch control stage configured to generate a plurality of switching signals having a duty-cycle. The system also includes an input stage comprising the primary inductor and a plurality of switches that are controlled in response to the respective plurality of switching signals to generate a primary resonant current and an output stage comprising the secondary inductor and being configured to conduct an output current through a load based on a secondary resonant current to generate an output voltage. The system further includes a controller configured to limit a magnitude of the output current to a predetermined magnitude in response to variations of the load.

Abstract: A switching power source device IS capable of guaranteeing a normal switching operation even when the input of a coil voltage used for adjusting a dead time is eliminated. The switching power source device includes a dead time adjustment circuit that generates an ON trigger signal that regulates an ON timing of one of the first and second switching elements after elapse of a predetermined dead time from an OFF timing of the other switching element and that adjusts the dead time according to a temporal change of a terminal voltage detected from an auxiliary coil of an inductor; and a disable control circuit that detects a temporal change of the coil voltage during activation and disables a function of the dead time adjustment circuit adjusting the dead time when the coil voltage does not temporally change.

Abstract: There is provided a resonance-type power supply apparatus capable of controlling primary side switching by estimating output power based on resonance current of the primary side. The resonance-type power supply apparatus includes a switching unit switching input power, a transformer including a primary winding receiving the power switched by the switching unit and a secondary winding magnetically coupled to the first winding and having a preset turns ratio, and transforming the received switched power according to the turns ratio, a resonance unit electrically connected between the switching unit and the transformer and providing a resonance tank resonating with inductance from the transformer, and a controlling unit controlling the switching of the switching unit based on resonance power information input to the primary winding of the transformer by the resonance unit.

Abstract: A circuit configuration contains a resonant converter feeding energy into a primary winding of a transformer, a control circuit for controlling the resonant converter and a plurality of modules. The modules include a frequency generator controllable with variable frequency, a short circuit monitoring unit configured to protect components of the resonant converter, and an open circuit detection unit. The open circuit detection unit is configured to shut down the resonant converter if a secondary side interacting with the primary winding of the transformer is open circuit, without having information from the secondary side.

Abstract: A control circuit performs at least one of detecting whether the resonance current detected by the current detection unit is beyond a first detection level over a predetermined time period, and detecting, when detecting that the resonance current is beyond the first detection level over the predetermined time period, that the resonance current falls below a second detection level, and detecting whether the resonance current detected by the current detection unit is below a first detection level over a predetermined time period, and detecting, when detecting that the resonance current is below the first detection level over the predetermined time period, that the resonance current exceeds a second detection level, and inverts, when detecting that the resonance current falls below or exceeds the second detection level, the levels of the drive control signal at which the first switching element and the second switching element are turned on or off.

Abstract: By setting switching instants of a switching circuit of a resonant power converter based on current in a resonant circuit reaching a current limit of a current limitation band, soft start-up of the power converter can be achieved to avoid or limit electrical stress with full control over a trade-off between time required to settle to a full load steady-state mode of operation and the amount of electrical stress permitted while soft start up switching frequency is automatically optimized.

Abstract: Pulse width modulation is provided for controlling a resonant power converter, particularly for dimming of light emitting diode arrays without loss of efficiency. Dynamic oscillation due to the beginning of a pulse width modulated pulse burst is limited by shortening of the first and/or last pulse of a pulse bust such that the first pulse of a subsequent pulse burst close to or to connect with a full load steady-state voltage/current trajectory of the power converter. Pulse shortening made be made substantially exact to virtually eliminate dynamic oscillation but substantial reduction in dynamic oscillation is provided if inexact or even performed randomly.

Abstract: A method for improving a power converter's efficiency comprises providing a resonant converter, wherein the resonant converter comprises an input coupled to a power source, a plurality of power switches coupled to the input, a resonant tank coupled to the plurality of power switches and a controller coupled to the power switches and generating a plurality of gate drive signals for the power switches, wherein the gate drive signals are arranged such that a switching frequency of the resonant converter is in a frequency band.

Abstract: A multi-stage power converter includes a pre-regulator circuit configured to provide a regulated output voltage, at least one DC/DC converter, and a control circuit coupled to the pre-regulator circuit and the DC/DC converter. The DC/DC converter is configured to provide an output voltage and an output current to a load. The DC/DC converter includes an input, an output, and at least one power switch. The input of the DC/DC converter is coupled to the pre-regulator circuit. The control circuit is configured to regulate the output voltage of the DC/DC converter and vary the regulated output voltage of the pre-regulator circuit as a function of the output current of the DC/DC converter.

Abstract: In an AC power supply apparatus, first and second switching circuits connected in series to an input terminal to which a DC input power supply is connected include first and second rectification elements, respectively. A capacitor, an inductor, and a capacitive load are equivalently connected in series to the second switching circuit. The capacitor is charged after the first switching circuit is turned on before the second rectification element is turned off and the charged capacitor is caused to discharge after the second switching circuit is turned on before the second rectification element is turned off. The above operations are periodically repeated. The voltage of the capacitive load is reversed with current flowing during the charge and the discharge of the capacitor to adjust the on and off periods of the first and second switching circuits in order to supply desired AC voltage to the capacitive load.

Abstract: An AC-to-DC power converting device includes: a filter for filtering an external AC input voltage; a rectifier for rectifying the AC input voltage filtered by the filter to output a rectified voltage; a power factor corrector for receiving the rectified voltage from the rectifier to generate a boosted voltage; and a step-down converter for receiving the boosted voltage from the power factor corrector to output a DC output voltage. The power factor corrector includes first and second capacitors connected in series across an output side of the rectifier, a series connection of a first diode, a first inductor, a third capacitor, a second inductor and a second diode coupled to the output side of the rectifier, and first and second switches connected in series across the third capacitor. A common node between the first and second capacitors is coupled to a common node between the first and second switches.

Abstract: A power converter includes a switching circuit, a power conversion circuit that receives an input voltage via the switching circuit and converts the input voltage into an output voltage, an input voltage sense circuit that detects the input voltage and generates an input voltage sense signal, and a PWM controller that adjusts a duty cycle of the switching circuit based at least in part on the input voltage sense signal. The power converter also includes an output sense circuit that detects the output voltage and generates an output voltage sense signal, wherein the PWM controller adjusts the duty cycle of the switching circuit based at least in part on the input voltage sense signal and the output voltage sense signal.

Abstract: A VHF switching power converter comprising one or more VHF switching frequency resonant synchronous rectifiers receives an output from an inverter and delivers a DC output to a load. The power converter includes a controller for controlling at least one of the one or more VHF switching frequency resonant synchronous rectifiers based on feedback derived from a waveform of at least one of the rectifiers. The controller controls a phase angle of at least one of the rectifiers with a delay locked loop. The power converter delivers a regulated DC output via adjustment of a phase shift between at least one of the one or more rectifiers and the inverter.

Abstract: The configurations of a parallel-connected resonant converter circuit and a controlling method thereof are provided in the present invention. The proposed circuit includes a plurality of resonant converters, each of which has two input terminals and two output terminals, wherein all the two input terminals of the plurality of resonant converters are electrically series-connected, and all the two output terminals of the plurality of resonant converters are electrically parallel-connected.

Abstract: An LLC resonant converter implements a primary-side current feedback scheme. The LLC resonant converter includes an isolation transformer having a primary winding and at least one secondary winding and is controlled by a control circuit to operate at a switching frequency. The LLC resonant converter includes a first capacitor connected to the primary winding through AC coupling to sense a first voltage indicative of a current flowing through the primary winding of the isolation transformer, and a current sense circuit configured to receive the first voltage and to generate a feedback signal. The feedback signal is coupled to the control circuit to regulate the switching frequency in response to the current at the primary winding. In another embodiment, the current sense circuit is a current and voltage sense circuit configured to sense a voltage at the primary winding.

Abstract: A multiphase DC-DC converter includes multiple groups of first and second LLC power trains coupled in parallel which collectively provide an output voltage to a load. A voltage feedback control loop senses an output voltage for the LLC converter and generates an identical reference current signal for each of the multiple groups of power trains, the signals representing a reference current based on the sensed output voltage, wherein an active current sharing operation is provided between each of the groups. A local current control loop for each of the groups generates PWM control signals to each of the respective first and second power trains based on the reference current, the PWM control signals having an identical frequency but out of phase with respect to each other, wherein a passive current sharing operation is provided within each of the plurality of power groups.

Abstract: In accordance with an embodiment, a power converter includes an H-bridge switching arrangement, a transformer having a primary winding coupled to an output of the H-bridge switching arrangement, a first switch coupled between a power input of the H-bridge switching arrangement and a first power supply node, and a second switch coupled between a center-tap of the primary winding of the transformer and a low impedance node.

Abstract: Methods and systems for current sharing using interleaved LLC power converters are described herein. The method provides for current sharing between a first LLC power converter interleaved with a second LLC power converter. The method includes determining an expected output voltage for at least one of the first and second LLC power converters and measuring an output voltage of at least one of the first and second LLC power converters. The method also includes increasing a dead-time of at least one of the first and second LLC power converters when the measured output voltage exceeds the expected output voltage. Finally, the method includes interleaving the first and second LLC power converters, wherein an output current of the first LLC power converter is substantially equal to an output current of the second LLC power converter.

Abstract: An AC/DC power converter utilizing a single stage boost-asymmetric LLC topology is disclosed. The converter uses a combined pulse width modulation (PWM) and frequency modulation (FM) to achieve dual control for a single main magnetic element (transformer). The transformer provides an output voltage regulation throughout the primary-secondary isolation operating in resonant mode (LLC) by means of frequency modulation, while at the same time its magnetizing inductance is conditioning the input current and providing a boosted high voltage for energy storage purpose by means of duty cycle control. A single pair of complementary primary switches is used to drive the primary winding of the transformer in order to achieve both voltage regulation and power conditioning. The secondary side capacitors and the resonant inductor, which may be either integrated into the transformer or external to the transformer, achieve the resonant function of the transformer.

Abstract: Methods and systems for calibrating an inductor-inductor-capacitor (LLC) resonant converter are provided herein. The method includes calculating input voltage mathematically as a function of at least one of an output voltage, a load current, and tolerances of components of the LLC resonant converter and operating the LLC resonant converter in an open loop mode at a nominal resonant frequency. The method also includes measuring output voltage of the LLC resonant converter and comparing the measured output voltage to the calculated input voltage.

Abstract: Methods and systems for improving load transient response in LLC converters are provided herein. The method includes coupling a current sensing circuit to an output of the LLC converter, sensing load current of the LLC converter, and increasing a setpoint voltage for a power factor correction (PFC) circuit output based on the sensed load current.

Abstract: A power converting device includes a switching unit, a resonant unit, a converting unit, a rectifying and filtering unit, an inductance-sensing unit, and a driver. The resonant unit is electrically connected to the switching unit and includes a resonant capacitor, a resonant inductor, and a variable magnetizing-inductor having at least two inductances, the resonant inductor is electrically connected to the resonant capacitor and the variable magnetizing-inductor. The converting unit is electrically connected to the resonant unit. The rectifying and filtering unit is electrically connected to the converting unit. The inductance-sensing unit is electrically connected to the rectifying and filtering unit, the inductance-sensing unit instantaneously senses inductances of the variable magnetizing-inductor.

Abstract: In the power supply composed of a driver circuit generating the carrier, a resonance circuit driven by the carrier and a rectification circuit generating the dc voltage by rectifying the amplitude-modulated carrier supplied by the resonance circuit and stabilizing the output voltage by the feeding back the voltage error between the output voltage and a reference voltage externally supplied to set up the output voltage, to the frequency and the amplitude of the carrier, the frequency response of the dc power supply is improved both by providing the pole located at the origin with a transfer function where the dc voltage, generated by rectifying and smoothing the output of the resonance circuit, is fed back to the frequency of the carrier and by not providing the pole at the origin with a transfer function where the dc voltage is fed back to the amplitude of the carrier.

Abstract: A non-isolated resonant converter is provided. The provided non-isolated resonant converter includes a switch circuit, a resonant circuit and a rectifying-filtering circuit. The switch circuit, the resonant circuit and the rectifying-filtering circuit are sequentially connected. The resonant circuit includes an auto-transformer, a capacitor and an inductor, wherein the capacitor and the inductor are connected to the auto-transformer. The configuration of the provided non-isolated resonant converter has small size, low loss and high power density.

Abstract: A resonant tank comprises a series resonant inductor coupled to a switching network and a transformer, a series resonant capacitor coupled to the switching network and the transformer, a first parallel inductor implemented as a magnetizing inductance of the transformer, a second parallel inductor implement as a separate inductor, wherein a first inductance of the first parallel inductor is greater than a second inductance of the second parallel inductor and a switch connected in series with the second parallel inductor.

Abstract: An adaptive inductive ballast is provided with the capability to communicate with a remote device powered by the ballast. To improve the operation of the ballast, the ballast changes its operating characteristics based upon information received from the remote device. Further, the ballast may provide a path for the remote device to communicate with device other than the adaptive inductive ballast.

Abstract: A primary side resonant circuit is formed by a primary side resonant inductor and a primary side resonant capacitor, and secondary side resonant circuits are formed by secondary side resonant inductors and secondary side resonant capacitors. Mutual inductances are formed equivalently through magnetic field resonant coupling between a primary winding and secondary windings, and a multi-resonant circuit that includes two or more LC resonant circuits is formed by a primary side circuit and a secondary side circuit. Electric power is transmitted from the primary side circuit to the secondary side circuit; resonant energy that is not transmitted from the primary winding and, of energy which the secondary winding has received, resonant energy that is not supplied to an output are each retained in the multi-resonant circuit; and, at the secondary side, the resonant energy is retained in a current path in which a rectifying element is not formed in series.

Abstract: An open loop half-bridge LLC power converter includes circuitry to reliably increase hold-up time without sacrificing efficiency. An LLC resonant circuit includes resonant inductance, a primary transformer winding, and resonant capacitance. An auxiliary circuit includes an auxiliary transformer winding, an inductor, and a third switching element coupled in series. A controller is coupled across a voltage sensor and effective thereby to determine a holdup time condition. In a “normal” operating condition the controller generates switch driver signals to turn OFF the third switching element and disable the auxiliary circuit, and in a hold-up time condition the controller turns ON the third switching element and enables the auxiliary circuit wherein the output voltage is increased via current supplied from the auxiliary winding. In various embodiments the auxiliary winding may be an auxiliary primary or secondary, or a secondary to an auxiliary primary winding of a second transformer.

Abstract: A power factor correct current resonance converter is disclosed which eliminates interference of switching operations between two cascade-connected converter circuits. The power factor correct current resonance converter includes a current resonance converter circuit having switches, a resonance capacitor, a resonance inductor, a transformer, diodes, a smoothing capacitor, and a control circuit. The power factor correct current resonance converter also includes a power factor correct converter circuit having a choke coil, a diode, a smoothing capacitor, and a switch. The switch is turned on or off in response to a voltage produced in a winding of the transformer. Thus, the switching operation of the power factor correct converter circuit is performed in synchronization with the switching operation of the current resonance converter circuit, so that interference of the switching operations is eliminated. In addition, since a dedicated control circuit is not required, the cost can be reduced.

Abstract: A DC to DC converter system, includes inverter circuitry having a first and a second switch, the inverter circuitry further configured to generate a first and a second gate control signal, the signals configured to open and close the first and second switch, respectively, and generate an AC signal from a DC input signal. The system further includes transformer circuitry configured to transform the AC signal into a sinusoidal AC signal, second stage circuitry configured to rectify the sinusoidal AC signal to a DC output signal, and hybrid control circuitry configured to modulate the first and second gate control signals, wherein the modulation comprises pulse frequency modulation (PFM) and pulse width modulation (PWM).

Abstract: A converter includes a rectifying circuit of an AC voltage of an AC power source into a rectified voltage, an input smoothing capacitor Ci, a first series circuit connected to the input smoothing capacitor and including a first and a second switching elements, a second series circuit connected to a connection point of the first and second switching elements and a first end of the input smoothing capacitor and including a primary winding of a transformer and a first capacitor Cri, a controller to alternately turn on/off the first and second switching elements, a rectifying-smoothing circuit (D1, Co) to rectify and smooth a high-frequency voltage of a secondary winding of the transformer into a DC output voltage, and a second capacitor connected between a connection point of the primary winding of the transformer and the first capacitor and a first end of the AC power source.

Abstract: A power converter and a method of converting power are provided. The power converter includes a resonant converting circuit and a control circuit. The resonant converting circuit converts an input power into an output power, and provides the output power to a load. The control circuit receives a feedback signal corresponding to the output power and the load, and outputs a driving signal according to the feedback signal to drive the resonant converting circuit. The control circuit selectively adjusts a duty period and an operating frequency of the driving signal according to a power required by the load.

Abstract: Consistent with an example embodiment, a resonant converter comprises a signalling transformer that is used to transfer information between the secondary winding and primary winding of the converter whilst maintaining mains isolation between the two sides. In the embodiment, according to the disclosure, the use of a signalling transformer (in addition to a switching, or resonant, transformer) eliminates the need for an opto-coupler to transfer information and so allows for the construction of a simpler, more reliable and/or cheaper resonant converter. Other embodiments described herein may be suitable for use in dimmable LED driver applications, for example.

Abstract: A single stage power factor correction power supply consists of two transformers: a main transformer and an auxiliary transformer (forward transformer). The main transformer transfers energy from the primary circuit to secondary circuit. The auxiliary transformer is used to correct input current waveform. The advantage of this design over the two stages power supply is that the voltage across storage capacitor can be designed to be only slightly higher than the peak value of the rectified input voltage. Therefore, it uses less energy to correct input current waveform and less EMC problem because it has less current through the inductor than two stage PFC power supply.

Abstract: A power converter including a resonant circuit is controlled by pulse width modulation (PWM) of a switching circuit to control current in the resonant circuit near the frequency of the resonant circuit (a null-immittance criterion) in order to control current and voltage at the output of the resonant circuit. Further control of voltage can be performed by PWM of a switching circuit at the output of the resonant circuit such that centers of the duty cycles of respective switches for the output of the resonant circuit are substantially synchronized and substantially symmetrical about centers of said duty cycles of respective switches at the input of the resonant circuit. Thus, operation of the converter is substantially simplified by using only PWM, a wide range of input and output voltages can be achieved and the converter circuit can be configured for bi-directional power transfer.

Abstract: A boost control section for controlling a converter includes a PI control section and a resonance suppression section. The PI control section calculates a basic command value based on a deviation between a drive voltage generated by the converter and a target voltage to equalize the drive voltage and the target voltage. The resonance suppression section calculates, based on the state of variation of the drive voltage, a correction value for correcting the basic command value to suppress the variation. The basic command value is corrected by adding the correction value. First and second drive pulses corresponding to the corrected command value are outputted to the converter.

Abstract: A circuit (1202) for a resonant converter (1204; 1326), the resonant converter configured to operate in a burst mode of operation, the circuit configured to: receive a signal (1206; 1308) representative of the output of the resonant converter; compare the received signal (1206; 1308) representative of the output of the resonant converter with a reference signal (1208; 1304) in order to provide an error signal (1310); and process the error signal (1310) in order to provide a control signal (1210; 1328), wherein the control signal (1210; 1328) is configured to set the switching frequency of the resonant converter in order to control the output power during the on-time of a burst of the resonant converter.

Abstract: Disclosed is a bi-directional battery power inverter (1) comprising a DC-DC converter circuit element (3) to which the battery (2) can be connected in order to generate an AC output voltage from a battery (2) voltage in a discharging mode while charging the battery (2) in a charging mode. The inverter (1) further comprises an HF transformer which forms a resonant circuit along with a resonant capacitor (6). In order to increase the efficiency of said battery power inverter, the transformer is provided with two windings (11, 12) with a center tap (20) on the primary side, said center tap (20) being connected to a power electronic center-tap connection with semiconductor switches (21, 31) while a winding (13) to which the resonant capacitor (6) is serially connected provided on the secondary side.