Abstract: Disclosed herein are a start-up circuit capable of reducing a leakage current to reduce power consumption, and a power device using the same. The start-up circuit includes: a bias unit connected between a first power source and a second power source and allowing a first current to flow from the first power source to the second power source according to a predetermined voltage; a first start unit connected to the bias unit and driving a second current to apply the predetermined voltage to the bias unit, and stopping driving the second current when a voltage received from the second power source reaches a first voltage; and a second start unit connected to the bias unit and driving a third current, the predetermined voltage being applied to the bias unit by the third current, and stopping driving the third current upon receiving a stop signal.

Abstract: A power converter is provided to improve connection reliability of internal components of the power converter. The power converter may include a power semiconductor module that converts DC current into AC current, a casing that forms a housing space for housing the power semiconductor module, an AC relay bus bar that is connected to an AC terminal of the power semiconductor module by weld connection, and an AC terminal block that is connected to an AC terminal of a motor. The AC relay bus bar may be supported by the casing through an insulating member, and the AC terminal block may be connected to the AC relay bus bar and supported by the casing.

Abstract: An AC-DC conversion circuit includes an input rectifier circuit, a primary side input filtering capacitor, a primary side inverter circuit, a drive circuit, an isolation transformer, a secondary side rectifier circuit, a secondary side capacitors, and a control circuit connected between the secondary side output filtering capacitor and the drive circuit, where the drive circuit is connected to the primary side inverter circuit. The primary side inverter circuit and the primary side input filtering capacitor form a loop, so as to form a clamping resonant circuit. Inverter switching transistors operate in a zero voltage switching (ZVS) state. The secondary side rectifier circuit has two operation modes including a forward operation mode and a flyback operation mode. Each of the first and the second inverter switching transistors in the primary side inverter circuit is used as an inverter switching transistor or a clamping switching transistor according to an operation period.

Abstract: One example embodiment is a method executed by a microcontroller with a Pulse Width Modulation (PWM) circuit to control a semi-dual-active-bridge (SDAB) converter that includes a first side bridge circuit, a second side bridge circuit and a transformer. The microcontroller determines a current operation mode and a target operation mode of the SDAB converter. The microcontroller determines an optimal ratio and calculates changes of each gating signal that are applied to the first side bridge circuit and the second side bridge circuit respectively.

Abstract: A power supply circuit includes a power amplifier that receives a direct current (DC) voltage from a first power source. A control signal applied to the power amplifier causes the power amplifier to convert the DC voltage to an alternating current (AC) output signal. The AC output signal is applied to a transformer that includes a first winding, a second winding, and a third winding. The first winding receives the AC output signal and the second winding receives an output current that varies in accordance with the AC output signal to apply current to a load. A rectifier includes a plurality of diodes configured to rectify a voltage across the third winding and clamp the voltage at the load. Return power from the third winding may be returned to the first power source.

Abstract: In an integrated circuit formed into a single chip, a drive signal generating unit generates drive signals for switching elements of a power conversion circuit. A monitoring unit monitors a microcomputer that calculates generation information that is information used to generate the drive signals, and determines whether or not an abnormality has occurred in the microcomputer. An angle converting unit converts an output signal of an angle sensor to rotation angle information of a rotating electric machine. A drive signal generating unit generates the drive signals for controlling driving of the rotating electric machine based on the generation information and the rotation angle information when the monitoring unit determines that an abnormality has not occurred in the microcomputer, and generates the drive signals based on the rotation angle information, without using the generation information, when the monitoring unit determines that an abnormality has occurred in the microcomputer.

Abstract: A bi-directional transmitter/receiver according to an embodiment includes a pin connected with a main control circuit, a transistor connected with a first electrode to the pin, a Schmitt trigger which determines an output according to a voltage of the pin, and a temperature sensor which is connected to the pin and which senses temperature and outputs temperature information to the pin. A driving circuit for controlling switching operation of one or more switches includes a bi-directional transmitter/receiver.

Abstract: A DC/DC converter has an active energy store, such as an inductance, which can be periodically charged and discharged by one or more semiconductor switches, such as transistors. To avoid voltage overshoot, an RCD element is provided for at least one semiconductor switch, wherein a capacitor and a diode of the RCD element are connected in series, and a resistor of the RCD element can be connected either in parallel with the diode or disconnected from the diode by a switch. The diode of the RCD element is arranged so as to be blocking in the conducting direction of the semiconductor switch.

Abstract: A current converter apparatus includes a multi-phase current converter having current-converter modules for each phase that are electrically connected to one another and arranged in a current-converter cabinet. Each current-converter module has at least one semiconductor component arranged on a heat sink and includes just two semiconductor components connected to each other and connected to be controlled by a control component. The current-converter modules in the current-converter cabinet are arranged so that the current-converter modules of each current-converter phase form a horizontal row of modules arranged one beside the other and the rows are arranged vertically one above the other.

Abstract: Provided is a method for controlling operation of semiconductor gates in a power conversion system including one or more multilevel inverters coupleable to a modulator and a controller. The method includes generating, via the controller, a control signal responsive to an output current power factor associated with the inverters and producing a discontinuous pulse width modulation reference signal based upon the control signal and a target output power, the discontinuous pulse width modulation reference signal being indicative of shifting a phase angle between current and voltage. A gating signal is generated for output from the modulator, as a function of the reference signal and a carrier waveform. The gating signal adjusts the phase angle to prevent switching of the semiconductor gates.

Abstract: An apparatus includes a first auxiliary switch connected to a positive connection of a switching leg of a DC-to-DC converter. The switching leg includes a first main switch and a second main switch connected at a main switch midpoint. A second auxiliary switch is connected between a negative connection of the switching leg and the first auxiliary switch. A connection point between the first and second auxiliary switches is an auxiliary midpoint. An auxiliary inductor connects the auxiliary midpoint and the main switch midpoint. The main switch midpoint is also connected to other converter elements. The first and second main switches include a first capacitance a second capacitance. A switch regulation module regulates the first and second auxiliary switches to control current in the auxiliary inductor to provide or remove charge from the first and second capacitances to induce zero voltage switching for the first and second main switches.

Abstract: An electronic circuit comprising a direct current interface at which a direct current is providable, an alternating current interface at which an alternating current is providable, a set of switchable half-bridges coupled to the direct current interface, each half-bridge comprising two blocks each having a switch and a diode, a control entity configured for switching the switches of the half-bridges with a predefined relative phase shift between different half-bridges, and a filter entity arranged between the alternating current interface and a plurality of parallel paths relating to the plurality of half-bridges wherein the filter entity comprises a coupled inductor inductively coupling the plurality of parallel paths.

Abstract: A switching converter includes a transformer having a primary winding to which an input voltage is supplied and formed of two primary winding halves, a tap between the winding halves, and a pair of switching elements in series connection with the winding halves. A voltage divider formed of two capacitors and across which the input voltage is supplied is connected at a center tap between the two capacitors to the primary winding tap through a damping element or network. Each switching element is connected through a respective driver to a controller that operatively effects synchronous control of the switching elements.

Abstract: A five level inverter comprises six switch tubes, two inductors, four capacitor units and two reverse current preventing devices. The common terminal of the third capacitor unit and the fourth capacitor unit is connected with the common terminal of the first capacitor unit and the second capacitor unit. The third capacitor unit and the fourth capacitor unit are used as the output filter circuit of the inverter, and the common terminal of the third capacitor unit and the fourth capacitor unit is used as the midpoint of the DC bus.

Abstract: An output transistor of an output circuit that outputs a large current may have a partial fault, but such a partial fault may not be detected because the transistor is very large. To address this, the invention provides an output circuit in which one output transistor is divided into a plurality of transistors, and a plurality of pads that are connected correspondingly to the transistors are provided. Fault detection can be performed on the plurality of transistors by using each pad. At least some of the pads are connected to one same output terminal of the substrate or the like.

Abstract: A power system having a plurality of operating modes including an active mode and an active standby mode includes a power converter and a controller the power converter is configured to adapt a power supply to a desired output, and the power converter includes a plurality of semiconductor switches that receive a gating signal when the power system is in the active mode such that the power converter is in a gating state. The controller controls the power converter in the active mode and the active standby mode, and the controller is configured to: while the power converter is synchronized to the grid, determine whether the power system should enter into the active standby mode in which the power converter is in a non-gating state; when it is determined the power system should enter into the active standby mode, control the power converter to be in a non-gating state such that the power system is in the active standby mode.

Abstract: According to a first aspect of the disclosure, there is provided a method of controlling a power output of an inverter. The method comprises measuring an output current of the inverter, determining a difference between the output current and a reference current, and controlling a reference input voltage of the inverter as a function of the determined difference. In a second aspect of the disclosure, there is described a system for controlling a power output of an inverter. The system comprises an inverter arranged to output a current as a function of a reference input voltage. The system further comprises a controller arranged to determine a difference between the output current and a reference current. The controller is further arranged to control the reference input voltage as a function of the determined difference.

Abstract: A semiconductor module, an upper and lower arm kit, and a three-level inverter can be provided at low cost and with broad current ratings and voltage ratings using existing packages, without developing new packages. A first semiconductor module (100) on an upper arm side and a second semiconductor module (200) on a lower arm side are made using an existing package, and the semiconductor modules (100) and (200) are used to configure an upper and lower arm kit (300). Further, the upper and lower arm kit (300) is used to configure a three-level inverter (500). These devices can be formed using existing packages (56), and semiconductor modules (100), (200), the upper and lower arm kit (300), and the three-level inverter (500) can be therefore provided at low cost and with broad current ratings and voltage ratings.

Abstract: A semiconductor device according to an embodiment includes a normally off transistor having a first source, a first drain, a first gate connected to a common gate terminal, and a body diode, a normally on transistor having a second source connected to the first drain, a second drain, and a second gate, a capacitor provided between the common gate terminal and the second gate, a first diode having a first anode connected to between the capacitor and the second gate and a first cathode connected to the first source, and a second diode having a second anode connected to the first source and a second cathode connected to the second drain.

Abstract: Provided is a semiconductor device which drives a power semiconductor device, in which dead times generated when switch elements of upper and lower arms are turned on and off are minimized, and a loss of a power conversion device is reduced. A semiconductor device used in a power conversion device that includes a first switch element of which the drain is connected to a first power source voltage and a second switch element of which the source is connected to a second power source voltage includes a first drive circuit that drives the first switch element, a second drive circuit that drives the second switch element, a first level shift circuit, and a second level shift circuit. The first drive circuit is connected to a third power source voltage higher by a predetermined potential with respect to a source potential of the first switch element and the source potential of the first switch element.

Abstract: A five-level active neutral-point-clamping inverter for converting a bipolar DC-voltage (VDC+ and VDC?) to a three-phase AC output voltage, the converter comprising first, second and third input terminals (P, MP, N) and first, second and third output terminals, where the inverter further comprises a first multi-state switching cell (MSSC) comprising three input terminals respectively connected to the input terminals of the inverter and a first output terminal, a second MSSC comprising three input terminals respectively connected to the input terminals of the inverter and a second output terminal and a third MSSC comprising three input terminals respectively connected to the input terminals of the inverter and a third output terminal.

Abstract: DC to AC multi-vector, multi-module switch mode converter capable of producing a fully regulated quazi-sinusoidal output voltage with cancelled N odd harmonics comprises two sets of 2N switch mode modules each with equal output amplitude operating with the output frequency and the means for summation of their outputs. Each switch mode module in the first set operates with its own fixed phase shift, in reference to the first module. Each module phase shift is calculated as a weighted sum of phase shifts for all harmonics to be cancelled ?n=?/n, where n is a number of harmonic and weights are defined by module number. The second set of modules is identical to the first set and produces its own output voltage with cancelled N harmonics too. The output voltages of the first and second sets are proportional to the DC bus voltage. The amplitude of the combined output voltage is regulated by the variable phase shift between the output voltages of the first and the second sets.

Abstract: A circuit for ensuring ultra-low power relay switching to control an AC load and extend a battery's lifetime. A control circuit may be designed to work where power is provided at very low duty cycles in that the on-time of applied voltage is quite short compared to its off-time. During the on-time, power such as that from a battery may be consumed to drive the circuit but overall such consumption of power is almost miniscule, for instance, a few microamperes or less from a three volt battery. An input FET may drive a pair of switching FETs that provide pulses to a transformer which provides a ramp of voltage that remains above zero volts to a pair of AC switch FETs. An output of the AC switch may go to operate relays of a wire saver for operating one or more thermostats.

Abstract: A method of prioritizing power output of first and second power-sources in a vehicle includes identifying, via a controller communicating with a satellite, the vehicle's position on a specific road course. The method also includes receiving a request for total amount of power from both power-sources and determining first power-source power and available second power-source target maximum power based on the vehicle position. The method also includes determining, based on the vehicle position, a minimum energy reserve of a source configured to energize the second power-source and available second power-source power based on the determined reserve. The method also includes subtracting the first power-source power from the requested total amount of power to determine a requested second power-source power. Furthermore, the method includes comparing the available and the requested second power-source power and generating the smaller power value to minimize the time for the vehicle to traverse the road course.

Abstract: A power converter includes first through sixth switching elements, first through tenth diodes, first through fourth capacitors, and a controller. The first through fourth capacitors are connected in parallel with the first through fourth switching elements, respectively. The seventh diode is connected in series with the first capacitor and is connected inversely in parallel with the first switching element. The eighth diode is connected in series with the second capacitor and is connected in parallel with the second switching element. The ninth diode is connected in series with the third capacitor and is connected inversely in parallel with the third switching element. The tenth diode is connected in series with the fourth capacitor and is connected in parallel with the fourth switching element.

Abstract: The disclosure relates to a method for operating an inverter that includes at least one bridge assembly that is actuated in a modulated manner for supplying electrical power to an energy supply network. Initially, the inverter is operated by the unipolar actuation of the at least one bridge assembly and the energy supply network is monitored for the presence of a network fault. If a network fault is detected, the inverter is operated at least at intervals by the bipolar actuation of the at least one bridge assembly. The disclosure further relates to a network fault-tolerant inverter which is equipped for carrying out the method.

Abstract: A switching circuit according to an aspect of the present disclosure includes: a full-bridge circuit including a first leg that includes a first switch and a second switch, and a second leg that includes a third switch and a fourth switch; and a control circuit operative to (a) output a first control signal group that changes the first leg into a state in which the third switch is off and the fourth switch is on after changing the first leg into a state in which the first switch is on and the second switch is off, and (b) output a second control signal group that changes the second leg into a state in which the third switch is off and the fourth switch is on before changing the first leg into a state in which the first switch is on and the second switch is off.

Abstract: Provided is a DC-AC conversion device capable of reducing ripple current output from a battery.

Abstract: A switching power supply circuit including a phase angle detector circuit detecting a phase angle specified in advance based on a peak hold signal, a continuous conduction control setting circuit holding a voltage value corresponding to a peak current value of an inductor current detection voltage in every switching cycle and during a one-shot pulse when the peak is held and outputting a signal at the point of detection to determine to enable or disable a second set pulse set by the continuous conduction control setting circuit. When the second set pulse is disabled, a selector circuit carries out control using critical conduction control to turn on a switching element using a ZCD comparator detecting that the inductor current has reached zero, because of which the peak current does not increase.

Abstract: In a discharging operation of a vehicle storage battery, a controller switches between a full-wave rectification operation of full-wave rectify a voltage across a second winding while maintaining a second short circuit in an open state, and a full-wave voltage doubling rectification operation of full-wave voltage doubling rectify a voltage across second winding while maintaining second short circuit in a closed state, based on magnitude relationship between DC voltage across first terminals and DC voltage across second terminals.

Abstract: According to the disclosure there is provided a method for characterizing an electrical connection between an energy storage device of an electrical or hybrid vehicle and an external power supply. The method may include, in the vehicle, receiving an alternating waveform from the power supply, determining a fundamental frequency of the waveform, determining if the waveform is distorted, and, if it is determined that the waveform is distorted, determining if the distortion is an indication of a loose connection between the vehicle and the power supply. There is further provided a charging system for characterizing an electrical connection between an energy storage device of an electrical or hybrid vehicle and an external power supply.

Abstract: The present invention relates to a circuit arrangement for electrical installations for converting and adapting a DC voltage of a voltage source, more particularly for a solar inverter of a photovoltaic installation, having an electrical output, which can be coupled to an inverter, wherein, at the electrical output, a potential in a positive branch of an intermediate circuit of the electrical installation can be increased in such a way that an output potential of a negative pole of the voltage source assumes a value greater than the potential of the negative pole before the increase, or the potential in a negative branch of the intermediate circuit of the electrical installation can be reduced in such a way that an output potential of a positive pole of the voltage source assumes a value lower than the potential of the positive pole before the reduction, and having a compensation device designed for compensating for the electrical power between the positive branch of the intermediate circuit of the electrical

Abstract: Provided are single phase and multiple phase DC-AC inverters with soft switching, and related methods and uses. The DC-AC inverters comprise at least one voltage source inverter circuit or at least one current source inverter circuit having a DC input and an AC output including a first component at a fundamental frequency and a ripple component at a frequency higher than the fundamental frequency; wherein the ripple component is of a sufficient magnitude that the voltage source inverter circuit output current reverses polarity and allows the at least one inverter circuit to operate with zero voltage switching; or wherein the ripple component is of a sufficient magnitude that the current source inverter circuit output voltage reverses polarity and allows the at least one inverter circuit to operate with zero current switching. The circuits and methods may be used with grid-connected renewable energy sources.

Abstract: For example, a semiconductor device has a lead connected to a second portion of a chip mounting part on which a semiconductor chip to be a heat source is mounted and a lead connected to a third portion of the chip mounting part on which the semiconductor chip to be the heat source is mounted. Further, each of the leads has a protruding portion protruding from a sealing member. In this manner, it is possible to enhance a heat dissipation characteristic of the semiconductor device.

Abstract: A system for converting a first voltage into a second voltage includes input terminals and output terminals, switching members disposed between the terminals which can convert voltage, and a device for controlling the switching members. The device includes a cell for controlling a switching member, and a member for managing and supplying the control cell. The member is connected to the control cell by a link allowing the simultaneous transmission of a control signal and electrical energy. The member includes a device for generating a pulse, and which includes at least two different control intervals.

Abstract: A dense and efficient output stage for a DC/DC converter includes center tapped secondary windings of a transformer having an offset core with respect to a PCB, two pairs of synchronous rectifiers configured to define two pairs of paralleled symmetrical AC loops respective to the secondary windings, and at least two bus bars disposed within a forced cooling airstream to act as heat sinks for the synchronous rectifiers, while further providing a filtering impedance between the transformer windings and an output capacitance. A split capacitance is disposed in close proximity with the synchronous rectifiers to filter out ripple current, in one embodiment characterized by first and second capacitors each respectively coupled between opposing ends of the first and second bus bars, wherein the bus bars are arranged about at least three sides of the transformer core.

Abstract: A motor drive controller includes: a phase current detection circuit including: an RC network circuit in which a resistor and a capacitor are connected in series, the RC network circuit being configured to be connected in parallel with one or more coils of each phase of a motor; and a filter circuit that smooths a signal based on a voltage signal across the capacitor, wherein the phase current detection circuit generates a DC voltage signal that corresponds to a change in a value of a phase current flowing in the coils; a motor driver that drives the motor by applying a voltage to each phase of the motor; and a controller that receives the DC voltage signal from the phase current detection circuit and controls the motor driver based on the DC voltage signal.

Abstract: A three-level converter and a method for controlling a three-level converter, wherein the third (S31, S32, S33), the fourth (S41, S42, S43) and the fifth (S51, S52, S53) controllable semiconductor switch of a switching branch having, out of all the switching branches, the most positive voltage in its alternating current pole (AC1, AC2, AC3) is controlled to be non-conductive for the whole period of time when the switching branch in question has the most positive voltage in its alternating current pole, and the first (S11, S12, S13), the second (S21, S22, S23) and the sixth (S61, S62, S63) controllable semiconductor switch of a switching branch having, out of all the switching branches, the most negative voltage in its alternating current pole is controlled to be non-conductive for the whole period of time when the switching branch in question has the most negative voltage in its alternating current pole.

Abstract: A semiconductor module is provided with a high potential wiring, an output wiring, a low potential wiring, an upper arm switching device, an upper arm diode, a lower arm switching device, and a lower arm diode. A ratio of steady loss to switching loss of the upper arm switching device is configured to be smaller than a ratio of steady loss to switching loss of the lower arm switching device. Further, a ratio of steady loss to switching loss of the upper arm diode is configured to be smaller than a ratio of steady loss to switching loss of the lower arm diode.

Abstract: A method of controlling a phase-shift full-bridge (PSFB) converter in a light load operation is provided to switch control modes of the PSFB converter by detecting magnetizing current of a transformer thereof. The method includes following steps: First, the PSFB converter is operated in an extended PSFB control mode when the magnetizing current is larger. Afterward, the PSFB converter is operated in a modified PSFB control mode when the magnetizing current is gradually reduced and electric charges transported by the residual magnetizing current near to or less than a half of the DC input voltage. Finally, the optimal degree of soft switching of the PSFB converter is implemented when the PSFB converter is operated at the modified PSFB control mode. Accordingly, it is to improve overall efficiency, reduce switching losses, and achieve electromagnetic compatibility.

Abstract: A switched mode power supply comprises a switched mode converter (12) and a controller for controlling the switched mode converter, wherein the switched mode converter is provided for converting an input voltage (Vin) to an output voltage (Vout) and includes, on a primary side, a primary winding (X1) and a controllable switch based circuitry (31) connecting the input voltage over the primary winding; and, on a secondary side, a secondary winding (X2) coupled to the primary winding, and a capacitive element (C) connected over the secondary winding, wherein the output voltage is obtained as the voltage over the capacitive element.

Abstract: A wireless power transmission system according to the present disclosure includes: a pair of antennas, between which power is transmissible wirelessly by resonant magnetic coupling at a frequency f0, one of which is a series resonant circuit, and the other of which is a parallel resonant circuit; and a control section, which controls a transmission frequency according to the magnitude of the power being transmitted between the antennas. If the power transmitted between the antennas is greater than a reference value P1, the control section sets the transmission frequency to be a value that falls within a first level range that is higher than the frequency f0. But if the power is smaller than the reference value P1, then the control section sets the transmission frequency to be a value that falls within a second level range that is lower than the first level range.

Abstract: An apparatus is capable of improving the power factor of a power supply powered by a high power line and a ground power line. The apparatus comprises a line voltage detector and an ON time controller. The line voltage detector provides a scaled voltage to represent a line voltage of the high power line. The ON time controller has a valley voltage detector, which provides, in response to the scaled voltage, a valley representative representing a valley voltage of the line voltage. The ON time controller controls an ON time of a power switch in the power supply in response to the valley representative.

Abstract: A system includes a first DC rail and a second DC rail, and a rectifier coupled with the first and second DC rails. A multilevel converter is also coupled with the DC rails and operable to limit input current harmonics to the rectifier. Differences between voltage phase and current phase in AC electrical power supplied to the system are compensated via closed loop control of a voltage output of the multilevel converter.

Abstract: The invention relates to an energy supply system having an energy storage device. The energy storage device has a plurality of energy storage modules that are serially connected in at least one energy supply branch, each comprising an energy storage cell module having at least one energy storage cell, and a coupling device having coupling elements configured to selectively switch the energy storage cell module into the respective energy supply branch, or to circumvent same, and comprising a plurality of driver devices, each dedicated to one of the energy storage modules, and coupled to one of the energy storage modules, and which are configured to actuate the coupling elements of the coupling devices according to a driver signal.

Abstract: A system and method for driving ultrasonic transducers and improvements to a phase track controller for reducing loss of lock occurrence is disclosed and described.

Abstract: A power factor correction (PFC) power converter is disclosed that converts AC input power to DC output power. A single stage of the PFC power converter performs both the DC-DC power conversion and the power factor correction for the power converter. The disclosed PFC power converters are efficient in energy conversion and have a power factor of 0.9-1.0. Further, the disclosed PFC power converters can be implemented in both low and high power applications above 75 W.

Abstract: A galvanically isolated DC/DC converter includes a first and a second side converter circuit coupled between a pair of first side DC terminals and a pair of second side DC terminals, respectively. The first side converter circuit has a first and a second switching element, each including a switch and a diode. When the DC/DC converter is in power transfer operation from the second side DC terminals to the first side DC terminals, the second side converter circuit alternates between two power transfer states. A conductive state of the diode of one of the first and second switching elements is the result of one of the two power transfer states. The first side converter circuit is controlled such that the switch of the respectively other of the first and second switching elements is closed for an adaptation interval before the one of the two power transfer states starts.

Abstract: The invention is directed to an inverter device and a power converting method thereof. A control unit adjusts a pulse width modulation (PWM) signal serving to control power conversion of an inverter circuit according to a current harmonic component detected by a detection unit to generate an offset current to be superposed to an AC current output by the inverter circuit.

Abstract: Systems, methods, and devices relating to DC/AC converters. A circuit including a full bridge inverter is provided. One leg of power semiconductor subcircuits of the inverter is switched at line frequency while the other leg is soft switched at a higher frequency using an auxiliary circuit. A control system is used to calculate this higher optimal frequency. To minimize the output current ripple in the output filter, the output inductor is coupled to the auxiliary inductor in the auxiliary circuit.