Abstract: A compact power adapter comprises an electric circuit, a casing and two electrically conductive AC prongs. A first portion of the casing contains the electric circuit. A second portion of the casing extends from a side of the first portion and has a generally cylindrical shape and size receivable in a car cigarette lighter. The second portion has two recesses and electrical contacts that receive electrical energy when the second portion is received in the car cigarette lighter. The AC prongs are receivable in an AC power outlet, and are rotatably coupled to the casing to rotate between a first position where the AC prongs extend from the casing approximately perpendicular to a longitudinal axis of the generally cylindrical shape of the second portion and a second position where each of the AC prongs is received in a respective one of the recesses of the second portion.

Abstract: According to one embodiment, a note PC has a disk drive connected to a system board via a connector. A power receive coil is attached to the disk drive. Power produced by the power receive coil as a result of excitation of a power feed coil is fed to a power supply control circuit via an unused pin of the connector.

Abstract: A portable power system for use with an electrical device. The system includes a portable power storage device, a motor, a controller, an alternator, an inverter, and a first monitor. The portable power storage device provides a DC voltage. The first monitor generates a first indication related to a characteristic of the portable power source. The controller monitors the primary power source delivering primary power to the electrical device, couples the portable power storage device to the inverter for generating an AC output, and selectively drives the motor in response to the first indication. The alternator is responsive to the motor for converting mechanical motion of the motor into an electrical signal for use to recharge the portable power storage device.

Abstract: An input adaptable electrical test set provides for the automatic detection of the power source connected to the test set, as well as automatic configuration of the test set to accommodate the identified power source. Prior to identification of the power source, a circuit breaker isolates a main transformer associated with the test set from receiving power from the power source. The main transformer includes a primary winding and a secondary winding, the primary winding having first, second and third tap positions that allows the transformer to be configured in one of two states depending on the power source connected to the test set. An automatic input voltage detection circuit monitors the input voltage provided by the unidentified power source and identifies the power source based on the monitored voltage.

Abstract: The present application discloses methods, circuits and systems for power conversion, using a universal multiport architecture. When a transient appears on the power input (which can be, for example, polyphase AC), the input and output switches are opened, and a crowbar switch shunts the inductance which is used for energy transfer. This prevents this inductance from creating an overvoltage when it is disconnected from outside lines.

Abstract: The present application discloses methods, circuits and systems for power conversion, using a universal multiport architecture. When a transient appears on the power input (which can be, for example, polyphase AC), the input and output switches are opened, and a crowbar switch shunts the inductance which is used for energy transfer. This prevents this inductance from creating an overvoltage when it is disconnected from outside lines.

Abstract: The present application discloses methods, circuits and systems for power conversion, using a universal multiport architecture. When a transient appears on the power input (which can be, for example, polyphase AC), the input and output switches are opened, and a crowbar switch shunts the inductance which is used for energy transfer. This prevents this inductance from creating an overvoltage when it is disconnected from outside lines.

Abstract: A portable electronic apparatus is connected to a power supply device via a transmission line, and it includes a designated connector, a charge control circuit, and a judgment circuit. The designated connector includes five terminals respectively corresponding to five pins of a USB connector of the power supply device. When the power supply device is connected to the portable electronic apparatus, the first terminal of the designated connector is logic high, the fourth terminal of the designated connector is logic high, and the third terminal of the designated connector is logic high after pulling up the voltage level of the second terminal, the judgment circuit pulls down the voltage level of the third terminal and detects the voltage level of the third terminal so as to generate a determining result for determining a type of the power supply device.

Abstract: Method and system for enhancing the power efficiency of a first wireless device that includes an energy receiver. In one implementation, the method includes receiving a transmitted signal at the first wireless device, converting the transmitted signal into power through the energy receiver, and providing the power to the first wireless device.

Abstract: Methods and systems for transforming electric power between two or more portals. Any or all portals can be DC, single phase AC, or multi-phase AC. Conversion is accomplished by a plurality of bi-directional conducting and blocking semiconductor switches which alternately connect an inductor and parallel capacitor between said portals, such that energy is transferred into the inductor from one or more input portals and/or phases, then the energy is transferred out of the inductor to one or more output portals and/or phases, with said parallel capacitor facilitating “soft” turn-off, and with any excess inductor energy being returned back to the input. Soft turn-on and reverse recovery is also facilitated. Said bi-directional switches allow for two power transfers per inductor/capacitor cycle, thereby maximizing inductor/capacitor utilization as well as providing for optimum converter operation with high input/output voltage ratios. Control means coordinate the switches to accomplish the desired power transfers.

Abstract: Methods and systems for transforming electric power between two or more portals. Any or all portals can be DC, single phase AC, or multi-phase AC. Conversion is accomplished by a plurality of bi-directional conducting and blocking semiconductor switches which alternately connect an inductor and parallel capacitor between said portals, such that energy is transferred into the inductor from one or more input portals and/or phases, then the energy is transferred out of the inductor to one or more output portals and/or phases, with said parallel capacitor facilitating “soft” turn-off, and with any excess inductor energy being returned back to the input. Soft turn-on and reverse recovery is also facilitated. Said bi-directional switches allow for two power transfers per inductor/capacitor cycle, thereby maximizing inductor/capacitor utilization as well as providing for optimum converter operation with high input/output voltage ratios. Control means coordinate the switches to accomplish the desired power transfers.

Abstract: The present application discloses methods, circuits and systems for power conversion, using a universal multiport architecture. When a transient appears on the power input (which can be, for example, polyphase AC), the input and output switches are opened, and a crowbar switch shunts the inductance which is used for energy transfer. This prevents this inductance from creating an overvoltage when it is disconnected from outside lines.

Abstract: A power supply includes an AC-to-DC circuit, a DC-to-DC circuit, an interface used by both of the AC-to-DC circuit and the DC-to-DC circuit, and a control circuit for controlling the interface. The interface includes an ACL/DC+ input terminal, an ACN/DC? input terminal and a ground. The control circuit includes an AC/DC detecting circuit for determining whether an input voltage is AC or DC, an AC/DC converting circuit for selectively conducting AC or DC, and a conversion-controlling circuit for controlling the direction of the input voltage based on the determination in the AC/DC detecting circuit.

Abstract: A modular laboratory automation system for monitoring and controlling laboratory experiments, the modular laboratory automation system including a controller, an interface board, and a portable power supply. Power levels of standard laboratory equipment can be automatically controlled, and conditions and parameters of experiments can be automatically monitored and recorded. The laboratory automation system is modular and can be configured to operate with laboratory experiments having varying setups and equipment.

Abstract: Power supply equipment includes low power assemblies and high power assemblies, each of which is detachably mateable to either one of two power ports. To simultaneously power two low power devices, low power assemblies are respectively mated to each of the power ports. To simultaneously power one low power and one high power device, a low power assembly is mated to one of the power ports and a high power assembly is mated to the other power port. The low power assemblies transfer a low DC voltage, but not a high DC voltage, to low power devices. The high power assemblies transfer a high DC voltage, but not a low DC voltage, to high power devices. If a high power assembly is mated to each of the power ports, power flow is interrupted without putting the power supply in an overvoltage or overcurrent condition.

Abstract: Methods and systems for transforming electric power between two or more portals. Any or all portals can be DC, single phase AC, or multi-phase AC. Conversion is accomplished by a plurality of bi-directional conducting and blocking semiconductor switches which alternately connect an inductor and parallel capacitor between said portals, such that energy is transferred into the inductor from one or more input portals and/or phases, then the energy is transferred out of the inductor to one or more output portals and/or phases, with said parallel capacitor facilitating “soft” turn-off, and with any excess inductor energy being returned back to the input. Soft turn-on and reverse recovery is also facilitated. Said bi-directional switches allow for two power transfers per inductor/capacitor cycle, thereby maximizing inductor/capacitor utilization as well as providing for optimum converter operation with high input/output voltage ratios. Control means coordinate the switches to accomplish the desired power transfers.

Abstract: Methods and systems for transforming electric power between two or more portals. Any or all portals can he DC, single phase AC, or multi-phase AC. Conversion is accomplished by a plurality of bi-directional conducting and blocking semiconductor switches which alternately connect an inductor and parallel capacitor between said portals, such that energy is transferred into the inductor from one or more input portals and/or phases, then the energy is transferred out of the inductor to one or more output portals and/or phases, with said parallel capacitor facilitating “soft” turn-off, and with any excess inductor energy being returned back to the input. Soft turn-on and reverse recovery is also facilitated. Said hi-directional switches allow for two power transfers per inductor/capacitor cycle, thereby maximizing inductor/capacitor utilization as well as providing for optimum converter operation with high input/output voltage ratios. Control means coordinate the switches to accomplish the desired power transfers.

Abstract: A portable hand held power inverter/converter having a pass through device for simultaneously sourcing A.C. and multiple voltage D.C. power consuming devices through a single D.C. power source connection. Inverter and converter circuitry is provided to invert and convert D.C. voltage to an A.C. voltage source and a lower DC voltage. A.C. electrical outlets are provided to facilitate a connection to an external A.C. power-consuming device and a DC outlet to a lower volt DC power-consuming device. The pass through device provides an independent and simultaneous connection to an additional D.C. outlet that would otherwise be eliminated when occupied by the inverter thus allowing simultaneous connection and operation of both A.C. and multi source D.C power consuming devices through a single external D.C. power outlet of a single D.C. power source.

Abstract: A DC-DC converter has a first-voltage-side port, a second-voltage-side port, and a third-voltage-side port, and performs, at different timings, an operation of boosting a first voltage to a third voltage and an operation of bucking a second voltage to the third voltage. A power supplying system includes a fuel cell, a secondary battery, an accessory system, the DC-DC converter, and another DC-DC converter connected between the fuel cell and a motor, and boosting the first voltage of the fuel cell to a fourth voltage to supply power to the motor through an inverter. The former DC-DC converter has the first-voltage-side port connected to the fuel cell, has the second-voltage-side port connected to the secondary battery, and has the third-voltage-side port connected to the accessory system.

Abstract: A portable electronic apparatus is connected to a power supply device via a transmission line, and it includes a designated connector, a charge control circuit, and a judgment circuit. The designated connector includes five terminals respectively corresponding to five pins of a USB connector of the power supply device. When the power supply device is connected to the portable electronic apparatus, the first terminal of the designated connector is logic high, the fourth terminal of the designated connector is logic high, and the third terminal of the designated connector is logic high after pulling up the voltage level of the second terminal, the judgment circuit pulls down the voltage level of the third terminal and detects the voltage level of the third terminal so as to generate a determining result for determining a type of the power supply device.

Abstract: Embodiments of DC power related systems and methods including a topology and devices to enable DC powered or driven constant current devices to be connected in a parallel configuration while maintaining a series connection internal to the devices.

Abstract: A modular power adapter and method for using the same which increases the ease of a user's travel with portable electronic devices. The modular power adapter includes an output module which may be interchangeably and detachably coupled to DC input module or an AC input module. The output module and the input module are provided in separate housing structures thereby effectively spreading the heat dissipated from the modular power adapter.

Abstract: An AC/DC intermediate-circuit converter has a very wide AC input voltage range with a ZVS three-level DC/DC resonant converter with an LLC series-resonant circuit. Two intermediate-circuit capacitors are connected in series between DC intermediate-circuit connections with their common connection point forming a DC intermediate-circuit center connection (5). The DC intermediate-circuit connections are connected to the DC connections of a rectifier whose AC input connections have an AC input voltage applied thereto. A range changeover switch is arranged between an AC input connection and the DC intermediate-circuit center connection. The range changeover switch is closed in a lower AC input voltage range, when the ZVS three-level DC/DC resonant converter is operated on the basis of a “two-level operating mode” modulation strategy, such that the LLC series-resonant circuit has the full DC input voltage present between the DC intermediate-circuit connections applied to it.

Abstract: An apparatus for efficient power supply operation variable input line voltages. The apparatus includes a detection module that senses the input line voltage to the power supply and determines whether it is high or low voltage. A turn module sets the turns ratio of the transformer to a first turns ratio if the input line voltage is low voltage. The turn module sets the turns ratio to a second turns ratio if the input line voltage is high. In one embodiment of the invention, a high voltage is between 180 and 250 volts, while a low voltage is between 90 and 130 volts. A primary module sets the boost voltage of the power supply's boost stage to a first voltage if the input line voltage is low, while it sets the boost voltage to a second voltage if the input line voltage is high. The first voltage may, for example, be 200 volts, and the second voltage 400 volts.

Abstract: A portable power supply for controlling laboratory experiments, the power supply includes input terminals that receive control signals and power terminals that supply power to laboratory devices. The power supply enables power levels of standard laboratory equipment to be automatically controlled.

Abstract: In a power converter, a primary winding receives an input power. In addition, multiple secondary windings transform the input power into multiple charging currents to charge a set of cells via a set of paths. The multiple secondary windings further balance the set of cells based on the charging currents. A ratio between a first turn number of a first secondary winding of the secondary windings and a second turn number of a second secondary winding of the secondary windings is determined by a nominal voltage ratio between two corresponding cells of the set of cells.

Abstract: To provide a power supply circuit which can be applied worldwide without using a high withstand voltage switching element and can supply a load device with stable power. A charging section is arranged between a turn-off capacitor and a load coil. The charging section has the anode connected to the positive terminal of a feedback coil and the cathode connected to the cathode of a zener diode. Thus, when a voltage of a commercial power supply is high, the charging section operates, the turn-off capacitor is quickly charged, an on-period of a transistor is shortened, and an excessive voltage is prevented from being applied between the drain and the source of the transistor. At the same time, an output characteristic indicating relationship between the voltage of the commercial power supply and a current flowing in the load device is permitted to be flat.

Abstract: A universal power adapter has an input for receiving an input voltage from a power source and an output for supplying an output voltage selected from amongst two or more preset voltages. A voltage converter circuit converts between the input voltage and the two or more preset voltages. A connector tip connectable with the output connects one of the two or more preset voltages to the output.

Abstract: A power supply includes an AC-to-DC circuit, a DC-to-DC circuit, an interface used by both of the AC-to-DC circuit and the DC-to-DC circuit, and a control circuit for controlling the interface. The interface includes an ACL/DC+ input terminal, an ACN/DC? input terminal and a ground. The control circuit includes an AC/DC detecting circuit for determining whether an input voltage is AC or DC, an AC/DC converting circuit for selectively conducting AC or DC, and a conversion-controlling circuit for controlling the direction of the input voltage based on the determination in the AC/DC detecting circuit.

Abstract: A power supply adapter is provided. The power supply adapter includes a power converter circuit configured to generate a regulated voltage signal. The power converter circuit includes a rectifier coupled with AC power blades. A regulator circuit is coupled with the rectifier. A transformer is coupled with the regulator circuit. The transformer includes a primary and a secondary. The transformer is coupled with the regulator circuit via the primary. An output circuit is coupled with the secondary of the transformer. The output circuit includes an output capacitor. A flexible contact is coupled with each of a first and a second printed circuit board and flexibly biased to couple with a proximate end of the AC power blades. The adapter includes an EMI shield substantially surrounding a connector receptacle. The power converter circuit can include a forward or a flyback power converter. The transformer can include a planar format transformer coupled with the first or the second PCB.

Abstract: A power controller (10) includes a controller (11) and a trigger circuit (12). When the voltage of a power supply received at terminals T1 exceeds a threshold, for example 120 V RMS, reverse-connected Zener diodes Z1 to Z3 conduct and switch on a transistor Q1. This results in a transistor Q2 being switched off and a normally open relay SW1 remaining open. The switching or triggering phase angle of a triac THY1 thus is determined by the speed at which a capacitor C4 is charged to a triggering voltage by current flowing through resistors R6, R7, R8 and VR1. In this situation, the triggering phase angle is such that a 240 V AC input supply provides an effective 110 V AC output at terminals T3 when VR1 is at maximum power setting (zero Ohms). When the voltage of the received power supply is less than the threshold, the transistor Q1 is switched off and the relay SW1 is activated.

Abstract: A power supply topology with pulse width modulation frequency control allows the use of an inductor with higher inductance in a converter. By controlling the switching frequency of the pulse width modulation signal, the inductor can achieve high efficiency during a light load condition and is also suitable for a heavy load condition.

Abstract: A mounting structure for a power module, in which a power module and a heat sink can be easily separated without additional labor and time and without requiring an extra disassembly space in a product and in which parts are not damaged during the disassembly. In the heat sink (5a), screw holes (7a) having female screw threads into which power module fixing screws (2a) are screwed are formed so as to penetrate a power module mounting surface (5c) of the heat sink (5a) and heat radiation fins (9a). The power module fixing screw (2a) is constructed such that, to mount the power module (3) on the heat sink (5a), the screw head of the power module fixing screw (2a) is tightened from the printed circuit board (4a) side with a tool (8a) and that, to remove the power module (3) from the heat sink (5a), the power module fixing screw (2a) is loosened with the tool (8a) from the heat radiation fin (9a) side on the opposite side of the screw head.

Abstract: A universal power adapter has an input for receiving an input voltage from a power source and an output for supplying an output voltage selected from amongst two or more preset voltages. A voltage converter circuit converts between the input voltage and the two or more preset voltages. A connector tip connectable with the output connects one of the two or more preset voltages to the output.

Abstract: An aircraft device power supply is capable of connecting to either an AC or a DC power bus provided on an aircraft. When connected to an aircraft's AC power bus, an AC power signal is EMI-filtered, stepped down in voltage to the same voltage as that of the DC power bus, and then rectified. When connected to an aircraft's DC power bus, a DC power signal is EMI-filtered before it is merged with the rectified AC power signal via an AC/DC switchover subcircuit. The output of the AC/DC switchover subcircuit is input to a power factor correction subcircuit which outputs a boosted DC voltage, regardless of which of the AC or DC aircraft power buses is connected to the power supply. A step down converter reduces the boosted DC voltage to a lower, system voltage which may then be further reduced or modified, as appropriate for device to be powered.

Abstract: A system interconnection inverter includes a step-up converter and an inverter. Moreover, the system interconnection inverter includes a short-circuit current-interrupting diode with a cathode connected to an input terminal of a negative bus, a semiconductor switch connected to an anode of the short-circuit current-interrupting diode, a semiconductor switch drive circuit that drives the semiconductor switch, a semiconductor switch-off circuit that turns off the semiconductor switch drive circuit when negative power is applied such that electric current flows from a cathode toward an anode of the input terminal, and a control circuit that controls the semiconductor switch drive circuit.

Abstract: An adaptive hybrid energy system is provided. The system includes a first DC energy source that generates a first DC output by converting a first type of energy into an electrical output. Additionally, the system includes at least a second DC energy source that generates a second DC electrical output by converting a second type of energy into an electrical output. The system further includes a cascaded multilevel converter electrically connected to the first and second DC energy sources to convert a DC electrical output into a sinusoidal electrical output when at least one of the first and second DC energy sources is operable.

Abstract: The present invention discloses a socket with power supply, comprising a housing having a upper cover and a lower cover which are connected together to form a receiving space; a transformer connected with an alternate current source through a plug protruding out of the first opening; at least a socket capable of outputting the alternate current; a rectifying circuit capable of rectifying the alternate current to direct current; and an output power plug coupled with the rectifying circuit and protruding out of the second opening through a power cord to output the direct current to an electronic device.

Abstract: An adapter connection structure, which includes a first converter and a second converter. The first converter is connected to at least one input terminal to receive an input power and converts the input power into a transitional power. The second converter is connected to the first converter via a transit cable to transmit the transitional power, converts the transitional power into a DC output power and outputs the DC output power via a DC power cable. As the transitional power transmitted from the first converter to the second converter is in the form of a high-voltage and high-frequency AC power or a high-voltage DC power, the power transmission loss in the transit cable is reduced. Therefore, the present invention reduces transmission loss.

Abstract: A power converter apparatus, such as an uninterruptible power supply (UPS), includes an inverter having an input coupled to a first DC bus and a second DC bus and configured to generate an AC output with respect to a neutral terminal at a phase output terminal thereof. The apparatus further includes first and second neutral coupling circuits, each configured to selectively couple the first DC bus and the second DC bus to the neutral terminal, and a control circuit configured to cause interleaved operation of the neutral coupling circuits.

Abstract: A power supply adapter includes a casing defining at least one inserting groove therein, at least one resilient piece disposed in the casing and having a locating portion and a resisting portion extended gradually upward from the locating portion, and a plug module rotatablely disposed in the casing. The plug module has at least one retaining block disposed in the inserting groove of the casing and capable of rotating around the resisting portion of the resilient piece. A connecting terminal runs through the retaining block to form an inserting portion and a projecting portion at opposite sides of the retaining block. The projecting portion is capable of compressing the resisting portion when the inserting portion is raised erectly to be exposed externally from the inserting groove.

Abstract: Methods and systems for transforming electric power between two or more portals. Any or all portals can be DC, single phase AC, or multi-phase AC. Conversion is accomplished by a plurality of bi-directional conducting and blocking semiconductor switches which alternately connect an inductor and parallel capacitor between said portals, such that energy is transferred into the inductor from one or more input portals and/or phases, then the energy is transferred out of the inductor to one or more output portals and/or phases, with said parallel capacitor facilitating “soft” turn-off, and with any excess inductor energy being returned back to the input. Soft turn-on and reverse recovery is also facilitated. Said bi-directional switches allow for two power transfers per inductor/capacitor cycle, thereby maximizing inductor/capacitor utilization as well as providing for optimum converter operation with high input/output voltage ratios. Control means coordinate the switches to accomplish the desired power transfers.

Abstract: Solar panels of certain technologies may experience a degradation of their efficiency as a result of exposure to sunlight, either prior to installation or during normal operation. A direct current to pulse amplitude modulated (“PAM”) current converter, denominated a “PAMCC”, is connected to the solar panel and to a source of alternating current. The PAMCC receives direct current from the solar panel and provides pulse amplitude modulated current at its output terminals at such times that the solar panel is capable to provide current, denominated “normal operation”. The PAMCC may be reconfigured to form a buck converter and a rectifier wherein the rectifier converts power received at the output (during normal operation) terminals to provide rectified, direct current to the buck converter. The buck converter provides direct current in the forward biased direction to the solar panel, thereby reconditioning the solar panel.

Abstract: A portable electronic device having integral programming circuitry for signaling a power converter connected thereto to provide suitable power signals. Integrating the programming circuitry into the portable electronic device reduces the manufacturing cost and size of the power converter cable connector that is directly coupled to the portable electronic device. Many embodiments of the present invention are provided, including integrating the programming circuitry as part of the portable device electronics, or, onto the portable electronic device connector itself. This programming circuitry can comprise of at least one electrical component that may be passive or active.

Abstract: A dual input AC/DC power converter (10) having dual inputs (12, 14) adapted to receive both an AC and DC input and provide a selectable DC voltage output (16) and a second DC output (18). The dual input AC/DC power converter (10) comprises a power converter circuit (20) having an AC-to-DC converter (22), a DC-to-DC booster converter (24), a feedback circuit (26), a filter circuit (25) and a DC-to-DC buck converter (28). Advantageously, the power converter (10) resolves many of system management problems associated with carrying all of the different interface components necessary to power a wide variety of mobile products from either an AC or DC power supply. In addition, the power converter (10) also advantageously includes dual output voltage terminals (16/18) to allow for multiple mobile devices of varying power requirements to be powered, simultaneously, by a single converter.

Abstract: A dual input AC/DC power converter (10) having dual inputs (12, 14) adapted to receive both an AC and DC input and provide a selectable DC voltage output (16) and a second DC output (18). The dual input AC/DC power converter (10) comprises a power converter circuit (20) having an AC-to-DC converter (22), a DC-to-DC booster converter (24), a feedback circuit (26), a filter circuit (25) and a DC-to-DC buck converter (28). Advantageously, the power converter (10) resolves many of system management problems associated with carrying all of the different interface components necessary to power a wide variety of mobile products from either an AC or DC power supply. In addition, the power converter (10) also advantageously includes dual output voltage terminals (16/18) to allow for multiple mobile devices of varying power requirements to be powered, simultaneously, by a single converter.

Abstract: An electrical timer system is provided that has a unique voltage converter that automatically converts various supply voltage values to the required operating voltage for a timing device without jumpers or special configuration at installation.

Abstract: A portable power storage and supply system having means for AC charging, DC charging, AC discharging and DC discharging wherein any one or any combination of the AC and DC charging and discharging can be carried at one time. The system includes an inverter, one or more battery modules and control means for controlling the AC and DC charging and discharging functions for safe and efficient operation. DC charging can include energy from a renewable energy source. The battery modules are separable from the system for providing DC energy for energizing automotive battery jumper cables or for energizing DC powered devices.

Abstract: Methods and systems for transforming electric power between two or more portals. Any or all portals can be DC, single phase AC, or multi-phase AC. Conversion is accomplished by a plurality of bi-directional conducting and blocking semiconductor switches which alternately connect an inductor and parallel capacitor between said portals, such that energy is transferred into the inductor from one or more input portals and/or phases, then the energy is transferred out of the inductor to one or more output portals and/or phases, with said parallel capacitor facilitating “soft” turn-off, and with any excess inductor energy being returned back to the input. Soft turn-on and reverse recovery is also facilitated. Said bi-directional switches allow for two power transfers per inductor/capacitor cycle, thereby maximizing inductor/capacitor utilization as well as providing for optimum converter operation with high input/output voltage ratios. Control means coordinate the switches to accomplish the desired power transfers.

Abstract: Energy loss due to driving a plurality of power supply units simultaneously in a low-current region is prevented, and a more stable load current is obtained. The generation of a load current in a small-current region from a pilot arc current is handled solely by the power supply unit U1, the remaining (N?1) power supply units U2 through U4 are driven when the small-current region is exceeded, and a current that is the composite of all the currents is fed to the load, whereby a stable plasma arc power supply is obtained in which power consumption in the low-current region is reduced.