Abstract: A method for controlling a power supply is disclosed. An example method includes deactivating the power supply in response to a first current through a first terminal of a power supply controller falling below a first threshold value. The power supply is activated in response to the first current through the first terminal rising above a second threshold value. Deactivating the power comprises causing a power switch coupled to a primary winding of the power supply not to receive a switching waveform for more than one cycle until the power supply is activated.

Abstract: A motor drive circuit for a rail vehicle has a step-up converter, which is disposed at the input of the motor drive circuit, and which converts a mains DC voltage, at the input of the motor drive circuit into an intermediate circuit DC voltage. A pulse rectifier, which is downstream from the step-up converter, can be connected at the output to a drive motor of the rail vehicle and it is capable of converting the intermediate circuit DC voltage of the step-up converter into a motor drive voltage for driving the drive motor. A control unit activates the step-up converter in operation such that the converter generates the predetermined rated intermediate circuit DC voltage for a mains DC voltage below a predetermined rated intermediate circuit DC voltage as the intermediate circuit DC voltage.

Abstract: A cascaded power converter having an auxiliary power supply operated from the second switching power stage provides efficient operation by activating the auxiliary power supply early in the startup process. A low energy transfer operating mode is initiated in the second switching power stage to charge the auxiliary power supply output without generating significant disruption at the load. After the first switching power stage is started and the intermediate node voltage has increased to a level sufficient to operate the second switching power stage, the final switching power stage enters a normal operating mode. The low energy transfer operating mode has a substantially reduced switching rate and pulse width from that of the normal operating mode.

Abstract: A primary-side sampled feedback system includes a sample acquisition phase during which the voltage across the clamp capacitor is sensed as a measure of the primary-reflect output voltage. One end of the clamp capacitor is ground-referenced during the sample acquisition phase. The sample circuitry, which may include a transformer-coupled input for receiving the gate drive of the secondary switch, may use secondary-side or primary and secondary side signals to generate the sample acquisition control pulse and clamp switch drive signal. The sample acquisition control pulse occurs when the secondary current reaches its minimum or zero.

Abstract: A switching power source device for supplying power to a load includes a series resonant circuit, a plurality of main switch elements or main switch element groups for switching a current path of the series resonant circuit, a transformer for inducing a secondary current from the series resonant circuit, a plurality of synchronous rectification switch elements for rectifying the secondary current, a maximum on width control circuit for ordering a start and a completion of a maximum on width to the synchronous rectification switch element in synchronization with a timing of turning on the main switch elements or the main switch element groups, and a synchronous control circuit. The circuit controls an on period of the synchronous rectification switch element so as to turn on the synchronous rectification switch element in synchronization with a particular timing, and turn off in synchronization with another timing.

Abstract: An embodiment provides a control method capable of controlling a switching-mode power supply to provide an output power source. The switching-mode power supply has a winding coupled to an input power source and controlled by a switch to be energized or de-energized. The maximum current peak through the winding is set to be a predetermined value. A discharge time of the winding in a switching cycle period is detected. The switching cycle period of the switch is controlled to keep the ratio of the discharge time to the switching cycle period as a constant.

Abstract: In one embodiment, a method of operating a switched-mode power supply that has a switch coupled to a drive signal is disclosed. The method includes deactivating the drive signal at a first instance of time, and comparing a power supply signal to a threshold after deactivating the drive signal. The method further includes activating the drive signal a variable period of time after the power supply signal crosses the threshold.

Abstract: This invention generally relates to a bootstrap circuit for a switch mode power supply, a controller for a switch mode voltage converter, a switch mode flyback converter comprising the bootstrap circuit, a switch mode forward converter comprising the bootstrap circuit, and a method of bootstrapping a switch mode power converter. The bootstrap circuit comprises: a current bleed impedance (Rht1) to bleed current from an input power supply (VH+); circuitry to deliver current from the input power supply (VH+) via the current bleed impedance (Rht1) to the base of a power switch (Q1) such that the power switch (Q1) is operable to amplify the current delivered from the internal power supply; a passive circuit (Dst) to provide the amplified current to a reservoir capacitor (Cdd); and the passive circuit element (Dst) further to substantially block reverse current flow from the supply input (Vdd) to the emitter of the power switch (Q1).

Abstract: The switching frequency of an LLC converter is controlled by a control unit to which a feedback circuit provides a first current dependent upon the output voltage of the converter. An oscillator circuit produces a sawtooth waveform at a frequency dependent upon the first current, up to a limit equal to a second current set by a resistor. Two complementary switch control signals are produced for controlling two switches of the converter for conduction in alternate cycles of the sawtooth waveform. A timer produces dead times between the two complementary switch control signals in dependence upon the second current. Another resistor provides a current constituting a minimum value of the first current, and a charging current of a capacitor in series with a resistor modifies the first current for soft starting of the converter.

Abstract: An inverter according to the invention includes an open circuit instructing device (ECU, Steps S5 to S8). The open circuit instructing device is for opening a switching circuit based on resistor inter-terminal voltage Vrb and resistor current Irb.

Abstract: Techniques are disclosed to regulate an output current through a load coupled to a power converter using a current source coupled to the load. For instance, one power converter according to the teachings of the present invention includes an energy transfer element coupled between an input of the power converter and an output of the power converter. A power converter controller is coupled to the energy transfer element to control a transfer of energy from the input of the power converter to the output of the power converter. A load is to be coupled to the output of the power converter. A current source is to be coupled to the load. The current source regulates the current flowing through the load to a threshold current value. The current source is coupled to sense a current through the load. A switch having a first and second end is also included. The first end is to be coupled to the load and the second end is coupled to the current source.

Abstract: An exemplary multiplexed direct current regulation output circuit (2) includes a feedback circuit (22), a sampling circuit (30), a power control chip (21), a first output (27), a second output (28), a first half wave rectifier circuit (23), a second half wave rectifier circuit (24), a first filter circuit (25), a second filter circuit (26), a transformer (20), and a balance control circuit (29). The transformer is configured to provide low voltages to the first output via the first half wave rectifier circuit and the first filter circuit in series, and provide high voltages to the second output via the second half wave rectifier circuit and the second filter circuit in series. The balance control circuit is configured to control a voltage at the second output.

Abstract: An alternating current power supply device is provided with switch elements Q1, Q2 for converting direct current power from a direct current power supply Vin into alternating current power; a transformer T1 for converting the voltage of the alternating current power converted by the switch elements into other voltage; a load 20 connected to an output terminal of the transformer; a first detecting circuit 30 for detecting a first electric signal indicating power to be supplied to the load; a second detecting circuit 40 for detecting a second electric signal indicating the voltage of the direct current power supply; a feedback circuit 50 for generating a feedback signal based on the first electric signal detected by the first detecting circuit and the second electric signal detected by the second detecting circuit; and a control circuit 10 for generating a control signal based on the feedback signal from the feedback circuit and controlling on/off of the switch elements by the control signal so that power to be

Abstract: An AC power supply system modulates a high frequency switching signal with a pulse width modulation (PWM) signal to produce a composite signal. The duty cycle of the PWM component of the composite signal is used to control the brightness of a cold cathode fluorescent lamp for backlighting a liquid crystal display.

Abstract: A single-stage switching power supply includes a transformer, a voltage level generation circuit, a first switching circuit, a second switching circuit, a rectifying and filtering circuit, a feedback circuit and a control circuit. The rectifying and filtering circuit is connected to the secondary winding assembly and the system circuit for generating an output voltage. The feedback circuit generates a feedback signal in response to the output voltage. In response to the feedback signal and an operating-status signal issued by the system circuit, the first and second switching circuits are alternately enabled under control of the control circuit such that electric energy of a first DC voltage is transmitted from the first primary winding assembly to the secondary winding assembly. The first switching circuit is disabled but the second switching circuit is enabled under control of the control circuit when the operating-status signal is at a standby operating status.

Abstract: Generally, a DC/DC converter and its associated devices and processes are presented herein. The DC/DC converter may be a switched mode converter that includes a plurality of switching devices that couple between the first and second power supply rails. A transformer is coupled to the switching devices such that the switching devices exchange electrical energy through the transformer. A rectifier is coupled to the transformer to rectify the waveform from the transformer into a substantially DC output. The DC/DC converter also includes clamp diodes to relieve voltage stress on rectifier diodes. Resistors may be coupled in series with the clamp diodes to reduce a reset time of the DC/DC converter and thereby prevent catastrophic failure of the power supply during load transients. Additionally, the DC/DC converter may be configured with a power outage detection device that monitors gate drive signals of the converter.

Abstract: A power supply apparatus and method of regulating is provided. A converter circuit includes a primary switching element and an auxiliary switching element. The auxiliary switching element is for transferring a reflected voltage signal. A transformer includes a primary and a secondary, the primary is coupled with the converter circuit. The primary and the secondary each comprise a single winding. An output rectifier circuit is coupled with the secondary of the transformer. A resonant circuit is included in the converter circuit and is coupled with the primary. The resonant circuit includes one or more resonance capacitors that are configured for providing a transformer resonance. The transformer resonance comprises the reflected voltage signal, the capacitance of the one or more resonance capacitors and a parasitic capacitance of the transformer. The reflected voltage signal is reflected from the secondary to the primary. A current feedback circuit is coupled between the primary and a controller.

Abstract: A self-coupled transformer boostbuck circuit includes a first transformer having a first winding, a second winding and a third winding, a first switch having a first voltage output at its one end, a second switch, a second transformer, a third switch having a second voltage output at its one end, a fourth switch, a fifth switch having a third voltage output at its one end, and a sixth switch.

Abstract: A ballast circuit that facilitates providing thermal protection for a fluorescent lamp includes a coupling transformer that couples an inverter circuit to a control circuit. First and second transformer windings in the inverter circuit, and a third transformer winding in the control circuit, are wound around a common ferrite core. The ferrite core has a Curie temperature that approximates a maximum allowable threshold temperature for the lamp. When the temperature of the ballast approaches the Curie temperature of the ferrite core, its permeability, and thus inductance, drops dramatically, causing an increase in operating frequency in the inverter circuit. This increased operating frequency causes a capacitor in the control circuit to charge to a threshold voltage, at which power to the inverter circuit is reduced. The lamp then dims without turning off until the temperature is reduced to an acceptable level.

Abstract: A power supply to improve an EMI characteristic and an electronic device having the power supply. The power supply includes a power converter to convert an alternating current (AC) power applied from outside to a direct current (DC) power, a ground portion to supply a ground power to the power converter and a noise attenuator to reduce noise by blocking a harmonic current generated by a driving of the power converter from passing through the ground portion. Accordingly, the stable ground power can be supplied to the internal elements by avoiding the potential change of the ground power and the noise caused by the flow of the harmonic current can be reduced by shortening the harmonic current path. Therefore, the EMI characteristic can be improved.

Abstract: A method for operating a power controller is provided. The method includes activating a rectifying FET upon a detection of an activation body diode conduction current occurring in the rectifying FET. The method generates an activation signal for a corresponding primary FET. The method further includes deactivating the corresponding rectifying FET upon a reception of a deactivation signal. The method further includes then deactivating the corresponding primary FET after delaying the deactivation signal, wherein the delay lessens a conduction time of a deactivation body current of the corresponding rectifying FET. The method further includes generating a deactivation signal and deactivating the corresponding rectifying FET upon a reception of the deactivation signal and deactivating the primary FET after delaying the deactivation signal. The delaying lessens a conduction time of a deactivation body current of the corresponding rectifying FET.

Abstract: A DC-DC flyback converter, includes a three-winding transformer; a primary power circuit having a first MOSFET connected to a first winding of the transformer; a secondary power circuit connected to a second winding of the transformer terminals; and a self-driven circuit connected to a third winding of the transformer. The secondary power circuit includes a synchronous rectifier in the form of a second MOSFET and the self-driven circuit further includes a delay drive circuit, an isolation differential circuit, a negative removal circuit having a third MOSFET and a synchronous rectifier trigger switch-off circuit for switching the synchronous rectifier to an off condition.

Abstract: A load driving device disclosed in the specification includes a power supply circuit for supplying to a load an output voltage converted from an input voltage, a detection voltage generation circuit for generating a detection voltage which varies depending on a magnitude of a voltage drop which across the load, and a control circuit for controlling the power supply circuit so that it performs output feedback control of the output voltage, on the basis of the detection voltage.

Abstract: Methods and apparatus to control a digital power supply are disclosed. An example method includes controlling a power factor controller by: receiving a first current signal flowing in a first stage of the power factor controller, receiving a second current signal flowing in a second stage of the power factor controller, determining a difference between the first current signal and the second current signal, determining if the magnitude of a measured current signal is above a predetermined threshold, activating an integrator to integrate the difference when the magnitude of the measured current signal is above a predetermined threshold, and outputting a first control signal and a second control signal to the power factor controller based on the output of the integrator.

Abstract: The present invention relates to a driving circuit of switch device. The present invention employs transformer isolated driving. The number of said transformers is two. The primary sides of the two transformers are connected to two driving modulators, respectively. The input terminal of a high frequency carrier signal and the input terminal of a driving signal are connected to the input terminal of a first driving modulator. The input terminal of a driving signal being connected with an inverter together with the input terminal of the high frequency carrier signal are connected to the input terminal of a second driving modulator. The first secondary side of the first transformer is connected to a power supply circuit which may provide a necessary voltage for turning on the switch device during a high level period of the driving signal.

Abstract: A power conversion circuit for decentralizing input current includes a capacitor, a first inductor, a first switching circuit, a first discharging circuit, a second inductor, a second switching circuit, a second discharging circuit, and a control circuit. Under control of the control circuit, the first switching circuit and the second switching circuit are alternately conducted, and the second switching circuit is successively conducted when the first switching circuit is shut off.

Abstract: A non-isolated and isolated both polarity non-inverting and polarity inverting switching DC-to-DC converters with three switches are provided with a basic voltage step-up DC gain characteristics and a very efficient operation without a danger of voltage overstress of any of the three switches over the full operating range from duty ratio of 0 to 1.0, thus resulting in wide input voltage operating range. The isolated extensions feature transformer with no DC-bias for efficient operation and small size. Full-bridge secondary side implementation further reduces the output filtering requirements.

Abstract: Primary and secondary regions are electrically insulated from each other. The first and second pulse transformers are provided to the respective transistors in the switching circuit. Secondary windings of the first and second pulse transformers are connected to control terminals of the transistors. The control circuit supplies switching voltages to primary windings of the pulse transformers based on a feedback signal fed back through a feedback line. A primary winding of a transformer, the switching circuit, and the secondary windings are disposed on the primary region. A secondary winding of the transformer, the primary windings, the feedback line, and the control circuit are disposed on the secondary region.

Abstract: A system and method for operating, or electrically communicating with, an electrical supply network are disclosed. A vehicle is coupled to the electrical supply network, a trigger causes a partial discharge of an electrical energy storage device of the vehicle into electric power network, discharging electrical energy into the electric power network from the vehicle.

Abstract: In accordance with the present invention, a power converter transformer for suppressing conduction EMI(ElectroMagnetic Interference) includes a primary winding positioned at a primary side; a secondary winding positioned at a second side and coupled with the primary winding; a parasitic capacitor connected between one end of the primary winding and one end of the secondary winding; a switching unit connected to the other end of the primary winding; a Y-capacitor connected between the switching unit and a ground terminal; an auxiliary winding positioned at the secondary side and coupled with the secondary winding; and an auxiliary capacitor connected between the one end of the primary winding and the auxiliary winding.

Abstract: Inverter bus structures, assemblies and associated methods are disclosed herein. One embodiment of the disclosure, for example, is directed to a power inverter including an inverter module for converting DC power to AC power, a printed circuit board carrying a capacitor array, a DC power source, and a bus structure. The bus structure is physically coupled each of the inverter module and the printed circuit board, and the bus structure electrically couples each of the inverter module, the printed circuit board to the DC power source.

Abstract: A switching power supply unit is provided, in which input terminals of an AC voltage can be made common to output terminals of an AC voltage. A first switching circuit is provided between a winding of a transformer and a main battery. A second switching circuit is provided between another winding of the transformer and input/output terminals. A third switching circuit is provided between the second switching circuit and the input/output terminals. Each of the first to third switching circuits includes a bidirectional switch (configured of a pair of one switching element and one diode connected in parallel to each other). A circuit for outputting an AC output voltage can be common to a circuit for inputting an AC input voltage to charge the main battery.

Abstract: A power supply apparatus and method of regulating is provided. A converter circuit includes a primary switching element and an auxiliary switching element. The auxiliary switching element is for transferring a reflected voltage signal. A transformer includes a primary and a secondary, the primary is coupled with the converter circuit. The primary and secondary each include a single winding. An output rectifier circuit is coupled with the secondary of the transformer. A resonant circuit is included in the converter circuit and is coupled with the primary. The resonant circuit includes one or more resonance capacitors that are configured for providing a transformer resonance. The transformer resonance comprises the reflected voltage signal, the capacitance of the one or more resonance capacitors and a parasitic capacitance of the transformer. The reflected voltage signal is reflected from the secondary to the primary.

Abstract: An inverter circuit includes a first driving transformer, a second driving transformer, a power voltage circuit, a high-side FET connected to a secondary winding of the first driving transformer, a low-side FET connected to a secondary winding of the second driving transformer and an inverter transformer connected to a driving node between the high-side FET and the low-side FET. Thus, a direct current path does not exist between a gate of the high-side FET and the driving node, so that a gate voltage of the high-side FET is biased more to a negative polarity.

Abstract: A device generates a signal representative of a current flowing through a load inductor of a converter, the converter having a first transformer including a primary winding driven with a pulse width modulated (PWM) voltage signal. The device may include a sense inductor magnetically coupled to the load inductor, and an integrator configured to integrate a voltage drop on the sense inductor and to generate a first signal representative of the current flowing through the load inductor with an offset. The device may further include a second transformer to be magnetically coupled to the primary winding of the first transformer and generating a second signal representative of a current flowing through the primary winding, and a peak detector configured to sample and hold a peak value of the second signal at every cycle of the PWM voltage signal.

Abstract: A resonant switched power converter having switching frequency controlled in response to an output voltage thereof achieves over-current protection such as at start-up or under short circuit conditions using a resonant tank circuit which provides a notch filter in addition to a band pass filter. A additional band pass filter provided in the resonant tank circuit achieves increased power transfer to a load and reduced circulating resonant currents and conduction losses. The inductances of the preferred LCLCL tank circuit or other tank circuit with two pass band filters and a notch filter may be integrated into a single electrical component.

Abstract: A method and apparatus for precharging a DC to DC power converter system is provided. The system includes a boost circuit for generating a boosted output voltage from an input voltage. The input voltage is monitored. A predetermined current limit is compared to a current in the boost circuit, and the current limited is increased when the input voltage is greater than a predetermined value.

Abstract: A resonant converter and burst mode starting method thereof are provided. The resonant converter includes a converting stage, a transformer to induce the output of converting stage from the primary side to the secondary side, a rectifying stage to rectify the output of the transformer, a filtering and load stage to filter the output of the rectifying stage, and a charge pump circuit coupled to the transformer or the rectifying stage. The charge pump circuit is for raising a voltage level of the filtering and load stage to higher than a predetermined value so that a feedback voltage of the resonant converter varies. The burst mode of the resonant converter is than started in accordance with the variance.

Abstract: Switching device for linking various electrical voltage levels in a motor vehicle, in which a drive voltage level has an electric drive machine which may be actuated by a power converter, and a drive energy accumulator which is associated with an intermediate circuit, and in which the drive voltage level is connected to a vehicle electrical system voltage level by an electrical converter. The electrical converter is designed as a coupling circuit which is connected at the drive side to at least one node point of a winding circuit of the electric drive machine and to a voltage potential relative to the intermediate circuit. The coupling circuit is connected at the vehicle electrical system side to the vehicle electrical system via a switching unit which has at least one non-diminishing, finite impedance.

Abstract: The present invention discloses a secondary side-driven half-bridge power supply, which has a half-bridge transformer. A MOSFET unit is connected to the primary side of the half-bridge transformer, and an output rectifier/filter circuit connected to the secondary side of the half-bridge transformer. In the present invention, a PWM controller generates a control signal and sends the signal to a separating element. The control signal is used to drive the MOSFET unit, and the MOSFET unit then drives the half-bridge transformer. The output rectifier/filter circuit processes the signal output by the half-bridge transformer to provide voltages for external loads. The present invention can increase the power efficiency, raise the working frequency, and reduce the cost.

Abstract: An AC power supply apparatus used for an AC load of a high voltage such as a cold cathode tube. When a cold cathode tube is caused to emit a light, a DC voltage is on/off controlled at a predetermined ratio; thereafter, an AC signal of a high frequency is applied to the on/off controlled voltage in an oscillator circuit; then the resultant signal is boosted up to a predetermined level of voltage in a booster circuit; and thereafter, the AC power supply of the high voltage is applied to the load such as the cold cathode tube.

Abstract: A contactless power supply has a dynamically configurable tank circuit powered by an inverter. The contactless power supply is inductively coupled to one or more loads. The inverter is connected to a DC power source. When loads are added or removed from the system, the contactless power supply is capable of modifying the resonant frequency of the tank circuit, the inverter frequency, the inverter duty cycle or the rail voltage of the DC power source.

Abstract: A DC-DC converter includes a switching circuit having first and second switching elements to which a direct current voltage is supplied, the first and second switching elements periodically operated so that one of the switching elements is turned on while the other one is turned OFF during a period other than a dead time period, a serial circuit in which a first capacitor, and primary windings of first and second inductance elements are connected in series, and a connection is made between an output point of the switching circuit and a reference potential point (or input voltage point), and output circuits including rectifier elements, each of which rectifies a voltage induced by secondary windings of the first and second inductance elements, the output circuits obtaining a direct current output voltage.

Abstract: A method for transmitting an information signal across an isolation barrier comprises receiving an input signal, preconditioning the input signal according to a modulation function, passing the preconditioned signal through the isolation barrier, and recovering the passed signal according to a demodulation function corresponding to the modulation function, the recovered signal being operative as a feedback signal.

Abstract: A bi-directional DC-DC converter uses a transformer for both step-down and step-up operations. A switching frequency for operating a switching device is set separately for the step-down and step-up operations. When, for example, the switching frequency during the step-up operation is lower than the switching frequency during the step-down operation, the range in which the duty ratio in PWM control can be controlled is widened, compensating for step-up ratio insufficiency. Conversely, step-down ratio insufficiency is compensated for by making the switching frequency during the step-down operation lower than the switching frequency during the step-up operation.

Abstract: A switching mode power supply (SMPS) and a driving method thereof are provided. The SMPS includes a power supply block that includes a first switch coupled to a first coil of a primary side of a transformer for converting an input voltage, wherein the power supply block supplies power to a second coil and a third coil of a secondary side of the transformer according to operation of the first switch; and a PWM signal generator determines a turn-on time of the first switch according to the input voltage, and the turn-on time is determined regardless of a power magnitude of an output terminal connected to the second coil. Accordingly, screen noise due to a ripple can be eliminated and stress on the switch breakdown due to excessive power input can be reduced to enable an SMPS with stable driving.

Abstract: A DC-DC converter and first and second bypass switch circuits are provided in parallel between an input pin and first and second output pins and operate in accordance with a combination of the voltage value of the input pin and the voltage value required for the first output pin. A start control circuit causes the DC-DC converter to operate unconditionally in a step-down mode during the period from when the DC-DC converter is started until the output voltage of the DC-DC converter becomes equal to the voltage of the input pin. An output slope control circuit synchronizes rising slopes of the output voltages of the first and second bypass switch circuits with a rising slope of the output voltage of the DC-DC converter.

Abstract: A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls a switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the frequency and pulse width controls the peak of the inductor current.

Abstract: A voltage reduction detection circuit for a switching power supply includes a first rectifier diode having an anode connected to the output terminal of a secondary winding; a second rectifier diode connected in parallel with the first rectifier diode and having a cathode connected to the output terminal; and resistors arranged to divide the voltage between the cathode side of the first rectifier diode and the anode side of the second rectifier diode. The circuit detects a voltage reduction in an AC power supply (feeding AC power to the switching power supply) based on variation in a voltage resulting from voltage division by the resistors.

Abstract: This invention is a multi-port power converter where all ports are coupled through different windings of a high frequency transformer. Two or more, and typically all, ports have synchronized switching elements to allow the use of a high frequency transformer. This concept and type of converter is known. This invention mitigates a number of limitations in the present art and adds new capabilities that will allow applications to be served that would otherwise not have been practical. A novel circuit topology for a four-quadrant AC port is disclosed. A novel circuit topology for a unidirectional DC port with voltage boost capabilities is disclosed. A novel circuit topology for a unidirectional DC port with voltage buck capabilities is disclosed. A novel circuit for a high efficiency, high frequency, bi-directional, AC semiconductor switch is also disclosed.