Abstract: Systems and methods may include balancing an unbalanced power cable using a transformer that has one or more phases by selecting a voltage on a tap handle; disposing a first bushing on one or more phases at a different voltage than the selected voltage; and balancing the unbalanced power cable based on the disposition of the first bushing on the one or more phases at the different voltage.

Abstract: A circuit for generating an output current and a method for generating an output current are provided. A voltage generator circuit is configured to generate at least two voltages. A digital circuit is configured to generate a pulse width modulation signal having a waveform characteristic that is controllable based on bits of configuration data received by the digital circuit. An averaging circuit is configured to receive the pulse width modulation signal and generate a bias voltage that comprises a weighted average of the at least two voltages. Weights of the at least two voltages are based on the waveform characteristic of the pulse width modulation signal. A voltage-controlled current source is configured to generate an output current based on the bias voltage.

Abstract: Coils are formed into a coil group for a single phase by serially connecting a plurality of coils so that the resulting magnetic flux distribution is a sine wave distribution. The coil group for a single phase is constituted by a plurality of coil sets, formed from two coils that are wound around two adjacent magnetic pole teeth, connected in series. Each coil set includes coils of the two magnetic pole teeth constituting that coil set wound in opposite directions to each other looking from the inside of the stator. An electrical wire extending from an end winding of each coil is turned back so as to run in a direction opposite to an electrical wire connection to a start winding of that coil, and is connected to either a start winding of the next coil or a connection terminal.

Abstract: A three-phase transformer including a primary portion and a secondary portion, the primary portion including a first body made of ferromagnetic material and primary coils, the secondary portion including a second body made of ferromagnetic material and secondary coils, the first body defining a first annular slot of axis A and a second annular slot of axis A, the primary coils including a first toroidal coil of axis A in the first slot, a second toroidal coil of axis A in the second slot, and one or more third toroidal coils connected in series, the third coils being wound around one of the legs, and passing via slots in the leg.

Abstract: A three-phase transformer including a primary portion and a secondary portion, the primary portion including a first body made of ferromagnetic material and primary coils, the secondary portion including a second body made of ferromagnetic material and secondary coils, the first body defining a first annular slot of axis A and a second annular slot of axis A. The primary coils include a first toroidal coil of axis A in the first slot, a second toroidal coil of axis A in the first slot, a third toroidal coil of axis A in the second slot, and a fourth toroidal coil of axis A in the second slot, the second coil and the third coil being connected in series.

Abstract: The present disclosure provides a high-power variable inductor and a filter employing the same. A provided variable inductor comprises a first inductor and a second inductor. The first inductor is connected to a first input terminal and to a first output terminal of a two-port circuit. The second inductor is connected to a second input terminal and to a second output terminal of the two-port circuit. The first inductor and the second inductor are symmetrical to each other and jointly surround an adjustable area for varying an inductance of the variable inductor.

Abstract: In some embodiments, the instant invention can provide an electrical system that at least includes the following: a three-phase inductor, having: a core, having: at least one first core segment, having a first shape; at least one second core segment, having a second shape; at least one third core segment, having a third shape; where the at least one first core segment, the at least one second core segment, and the at least one third core segment are configured to be: separate from each other and adjustable relative to each other; and where the core is configured so that differential mode inductance flux paths during the operation of the three-phase inductor depend on the first shape of the at least one first core segment, the second shape of the at least one second core segment, and the third shape of the at least one third core segment.

Abstract: An inductive device includes an inductor having an inductance associated therewith, and a tuning ring disposed around the inductor. The tuning ring has an inductance associated therewith, wherein the tuning ring is coupled to the inductor to establish a mutual inductance between the tuning ring and the inductor. The inductance of the inductor, the inductance of the tuning ring, and the mutual inductance between the tuning ring and the inductor contribute to a total inductance of the inductive device. The tuning ring is configurable, and is selectively configured to achieve a certain value for the mutual inductance, and a certain value for the inductance of the tuning ring, without changing a footprint of the tuning ring.

Abstract: The present application relates to circuitry having a plurality of inductors, each inductor having a first end and a second end; and a switching arrangement connected to the first end and to the second end of each of the plurality of inductors for routing a current via the inductors; wherein the switching arrangement is arranged to at least one of selectably prevent current from flowing through a subset of the plurality of inductors and select a current flow direction through one of the inductors relative to a current flow direction through at least one other of the inductors so as to vary an effective inductance that the plurality of inductors represents to the current.

Abstract: A trimmable inductor assembly is provided for optimal balancing of phase currents in a multi-phase resonant converter. A magnetic device includes first and second core portions defining an outer edge of the device having a first axis, and further defining a first air gap. A bracket is positioned proximate the outer edge of the device and a magnetic plate is coupled to the bracket, with the magnetic plate and the second core portion defining a second air gap. A positioning device is coupled to the bracket and is responsive to control signals based on a detected phase current imbalance to drive the bracket and the magnetic plate between a first position defining a minimum air gap for the assembly and a second position defining a maximum air gap for the assembly.

Abstract: A three phase transformer circuit is provided that includes a supply side, wherein the supply side is selectably configurable, via the use of sets of terminal boards, between a delta connection and a wye connection at a time of use and, a load side, wherein the load side is selectably configurable between a delta connection and a wye connection at the time of use. The three-phase transformer also provides for selecting an input voltage, from multiple input voltages, via the sets of terminal boards, at the time of use, and for selecting an output voltage for the supply side, from multiple output voltage, at the time of use.

Abstract: The present disclsure relates to a resonant circuit (20). The resonant circuit is comprises three resonant circuit input nodes (11, 12, 13) and three resonant circuit output nodes (21, 22, 23), a transformer device and resonant tank devices. The transformer device (TR) comprises three primary windings (LP1, LP2, LP3) and three secondary windings (LS1, LS2, LS3) magnetically connected to each other, where the three secondary windings (LS1, LS2, LS3) are connected to the three resonant circuit output nodes (21, 22, 23). The first, second and third resonant tank devices (RT1, RT2, RT3) are each connected between the respective three resonant circuit input nodes (11, 12, 13) and the respective primary windings (LP1, LP2, LP3). The disclosure also relates to a resonant DC-DC converter comprising such a resonant circuit (20).

Abstract: An inexpensive variable inductor has inductance value continuously changeable without reducing a Q value. When a control voltage is applied to a control terminal of a MOS transistor from a power supply, a continuity region is formed in a channel, and a region between main terminals becomes conductive. When the control voltage is changed, length of the continuity region in the channel is changed. This changes length of a path area of an induced current, flowing in an induced current film. Thus, the amount of induced current is increased or decreased. Therefore, when the control voltage of the MOS transistor is changed, the inductance value of the coil is continuously changed.

Abstract: A polyphase transformer (1) comprising at least a first leg (2, 51) and a second leg (3, 52) of a magnetic material is described. The transformer comprises a single core with legs (2-4, 51-53) and yokes (27, 28, 54, 55). A primary winding (9, 15, 21, 56, 60, 62) is arranged on each one of the legs (2-4, 51-53) arranged to produce primary magnetic fields in the legs (2-4, 51-53), a secondary winding (12, 18, 24, 59, 61, 63) is arranged on each one of the legs (2-4, 51-53). The winding axis of the primary winding (9, 15, 21, 56, 60, 62) and the winding axis of the secondary winding (12, 18, 24, 59, 61, 63) are essentially parallel to each other on each one of the legs (2-4, 51-53). The transformer (1) also comprises at least one control winding (33-35, 45-47, 48, 49, 73-75) arranged to produce magnetic fields in each one of the legs (2-4, 51-53) being essentially orthogonal to the primary magnetic fields in the legs (2-4, 51-53).

Abstract: A variable inductor is provided. The variable inductor includes a dielectric core having a helical thread on an outer surface thereof for receiving the coil, and a non-magnetic element positioned coaxially within the core. The non-magnetic element could be provided in the form of a bushing or a solid rod, and could be manufactured from any suitable, non-magnetic metal, such as copper, brass, etc.

Abstract: A transformer arrangement comprising a transformer having a neutral and formed as a symmetrical transformer, in particular a cage transformer and having a reactor coil connected to the neutral of the transformer is provided. The transformer can be of any type having a neutral such as a Y-n/Y-n, Z-n/Z-n, Y-n/Z-n or a Z-n/Y-n transformer. By providing a transformer having symmetrical phases connected to a reactor coil a transformer arrangement having less weight is obtained. The lower weight is obtained because in comparison to using an E core for the transformer all phases will be symmetrical so that if a ground fault occurs in one of then phases there is no need for any compensatory windings regardless of which phase suffers the ground fault.

Abstract: A device for controlling a magnetic flux in an electromagnetic system, wherein the system includes magnetically connected magnetic cores, between which a volume is arranged. The volume includes a controllable magnetic flux region and the magnetic flux region includes a magnetic material having a relative permeability that may be varied by influencing the temperature of the material. The magnetic material includes a magnetic material, the Curie point of which lies within the temperature operating range of the device and exhibits paramagnetic properties within the temperature range. Also a method of controlling a magnetic flux.

Abstract: A biased gap inductor includes a first ferromagnetic plate, a second ferromagnetic plate, a conductor sandwiched between the first ferromagnetic plate and the second ferromagnetic plate, and an adhesive between the first ferromagnetic plate and the second ferromagnetic plate, the adhesive comprising magnet powder to thereby form at least one magnetic gap. A method of forming an inductor includes providing a first ferromagnetic plate and a second ferromagnetic plate and a conductor, placing the conductor between the first ferromagnetic plate and the second ferromagnetic plate, adhering the first ferromagnetic plate to the second ferromagnetic plate with a composition comprising an adhesive and a magnet powder to form magnetic gaps, and magnetizing the inductor.

Abstract: Electrical devices having tunable electrical characteristics are provided, such as variable resistors, capacitors and inductors. The tunable electrical characteristics are achieved by placing an appropriate material between substrate layers and by controllably applying a pressure to the material to compress the material or alter the shape of a well in which the material is contained, and thereby alter the electrical characteristics of the electrical device. The composition, shape and dimension of the embedded materials determine how the electrical characteristics of the electrical device are altered upon compression of the embedded material in response to an applied control signal. Generally, as the embedded material is compressed, the material will become more dense and the electrical characteristics of the integrated electrical device is altered.

Abstract: A transformer includes taps by which electrical contact can be made to winding sections of the transformer at locations along its length between its end terminals. A first switch permits contact to be made selectively to a selected one of the taps. An amplifier has an inverting input terminal, a non-inverting input terminal and an output terminal. The output terminal of the amplifier is coupled to the first switch so that selectively making contact with one of the taps couples the selected tap to the output terminal of the amplifier.

Abstract: An inductor includes a first wiring layer, a second wiring layer, a first conductive trace, a second conductive trace, a third conductive trace, and a fourth conductive trace. The first conductive trace is on the first wiring layer and the second conductive trace is on the second wiring layer. The third conductive trace is parallel to the first conductive trace and is on the first wiring layer. The fourth conductive trace is parallel to the second conductive trace- and is on the second wiring layer. The first end of the first conductive trace is connected to the first end of the second conductive trace through a first via plug. The second end of the second conductive trace is connected to the first end of the third conductive trace through a second via plug. The second end of the third conductive trace is connected to the first end of the fourth conductive trace through a third via plug.

Abstract: A variable inductor which avoids electrical breakdown of the insulation in the control windings when used in high power applications includes a core formed of a permeable magnetic material, the core having three legs, including a center leg and two outer legs. A main winding element comprising a main conductor is wound around the center leg of the core. A control winding element comprising a control conductor is wound in a figure-eight configuration having a first winding and a second winding around respective outer legs, the winding configuration canceling induced voltages in the first and second windings, wherein a current through the control winding element causes a change in inductance of the main winding element.

Abstract: An on-chip multiple tap transformer balun includes a 1st winding and a 2nd winding having two portions. The 1st winding is on a 1st layer of an integrated circuit and is operably coupled for a single ended signal. The 1st and 2nd portions of the 2nd winding are on a 2nd layer of the integrated circuit. The 1st portion of the 2nd winding includes a 1st node, a 2nd node, and a tap. The 1st node is operably coupled to receive a 1st leg of a 1st differential signal and the 2nd node is coupled to a reference potential. The tap of the 1st portion is operably coupled for a 1st leg of a 2nd differential signal. The 2nd portion of the 2nd winding includes a 1st node, 2nd node, and tap. The 1st node is operably coupled to receive a 2nd leg of the 1st differential signal and the 2nd node is operably coupled to the reference potential. The tap of the 2nd portion is coupled for a 2nd leg of the 2nd differential signal.

Abstract: A microelectro-mechanical device which includes a fixed electrode formed on a substrate, the fixed electrode including a transparent, high resistance layer, and a moveable electrode formed with an anisotropic stress in a predetermined direction and disposed adjacent the fixed electrode. The device includes first and second electrically conductive regions which are isolated from one another by the fixed electrode. The moveable electrode moves to cover the fixed electrode and to electrically couple to the second conductive region, thus electrically coupling the first and second conductive regions, in response to a potential being applied across the fixed and moveable electrodes. The fixed electrode is transparent to electromagnetic signals or waves and the moveable electrode impedes or allows transmission of electromagnetic signals or waves.

Abstract: A digital input PWM power amplifier includes an oversampling and noise shaping circuit receiving pulse code modulated (PCM) digital input data organized in words of a first number of M bits at a bit rate, and outputting PCM digital data organized in words of a smaller number of N bits at a multiple bit rate. A first bus transmits a first number of most significant bits (MSB) of the N bit words output from the oversampling and noise shaping circuit, and a second bus transmits a second number of least significant bits (LSB) of the N bit words output from the oversampling and noise shaping circuit. First and second PCM/PWM converters are respectively fed with the first and second number of bits transmitted through the first and second buses. The PWM signal output by the first converter is summed to an attenuated PWM signal output by the second converter on the inverting input node of the output power stage.

Abstract: This invention relates to a cooling system for a transformer Cooling panels of a radiator are fluidly connected to the transformer. Plates are positioned adjacent to or toward the ends of the cooling panels to form an enclosed flow path thereby increasing the velocity of air therein.

Abstract: Harmonic distortion in a multiple phase power system is controlled by enabling different phase relationships to be set, and changed, in the field, between the devices being energized and the power source providing the energization. This has particular application, for example, in canceling harmonics caused by multiple six-pulse variable frequency drives used for controlling connected three-phase induction motors that operate electric submersible pumps. A transformer used to achieve this has two winding groups, each with two sets of contacts at different phase relationships.

Abstract: A microelectro-mechanical device which includes a fixed electrode formed on a substrate, the fixed electrode including a transparent, high resistance layer, and a moveable electrode formed with an anisotropic stress in a predetermined direction and disposed adjacent the fixed electrode. The device includes first and second electrically conductive regions which are isolated from one another by the fixed electrode. The moveable electrode moves to cover the fixed electrode and to electrically couple to the second conductive region, thus electrically coupling the first and second conductive regions, in response to a potential being applied across the fixed and moveable electrodes. The fixed electrode is transparent to electromagnetic signals or waves and the moveable electrode impedes or allows transmission of electromagnetic signals or waves.

Abstract: A three-phase transformer having a variable output utilizes an auxiliary winding to minimize the number of switches or taps required to provide a plurality of output voltages. At least two output windings or coils each have a plurality of taps corresponding to varying percentages of output voltages. Although each output winding has at least one tap at the same voltage level, one of the output windings has an additional tap corresponding to a different output voltage level. The auxiliary winding, which preferably has a number of coil turns equal to that corresponding to the spacing between the different voltage levels on the output winding, permits one output winding to be set at a different voltage level than the other output winding. The auxiliary winding includes a pair of terminals which are alternately operable to balance the level and phase of the overall output voltage of the three-phase transformer.

Abstract: A phase shifting transformer or autotransformer for a three phase power distribution network in which selected outputs have a low zero phase sequence impedance. At least one low zero phase sequence impedance output is fed by a plurality of windings distributed amongst the three core legs such that the number of turns of windings generating a flux in the positive direction is substantially equal to the number of turns of windings generating a flux in the negative direction. Thus, according to the invention, the transformer may be provided with any necessary phase shifting angles between different harmonic sources, with some or all outputs having a low zero phase sequence impedance to reduce voltage distortion created by zero phase sequence harmonics.

Abstract: High frequency reactors for interconnecting a high frequency electrical power source and a load which reactors include a pair of plates having opposite surfaces with a length and width and a thickness between the surfaces which is small relative to the length and width of the surfaces. The plates are disposed with opposing closely spaced surfaces insulated from each other, and each of the plates has longitudinally aligned first and second portions with one portion of one of the plates electrically insulated from another portion of the plates and conductively interconnected by a variable reactance with another portion of the plates.

Abstract: A three phase transformer having a pair of additional coupled windings on the secondary side of each phase, with these coupled windings properly connected in series to develop a voltage in phase with a particular secondary voltage but driven from alternate phase primaries. The primary and secondary windings are connected in a Y or .DELTA. configuration. One coupled winding from each of the two phases, other than the desired secondary phase which is to be balanced, are joined in negative series so that when summed, they are aligned with the secondary phase being corrected. The series coupled windings are connected in parallel with the third secondary. The unbalanced current is split between the secondary winding and between the two coupled windings, each of which is coupled to the primary of another phase. The coupled winding combined voltages and resistances are approximately equal to the voltage and resistance of the secondary.

Abstract: A phase shifting polygonal transformer or autotransformer for a three phase electrical distribution system is provided, in which the transformer output winding or autotransformer winding is composed solely of three main coils and three auxiliary coils, alternately interconnected in series. The outputs for the transformer/autotransformer are connected to taps in the coils offset from the connections between coils, which eliminates the need for multiple auxiliary coils in each phase. The transformer/autotransformer of the invention is thus much simpler and less expensive to manufacture than a conventional phase shifting transformer or autotransformer, but reduces harmonics just as effectively.

Abstract: A phase-shifting transformer including main and series transformer units comprises a six-phase core including six independent magnetic circuits, numbered first through sixth from right to left. The combined U-, V-, and W-phase windings of the main transformer unit link with the fifth, third, and first magnetic circuits, respectively. The combined a-, b-, and c-phase windings of the series transformer unit link with the sixth, fourth, and second magnetic circuits. The winding directions of the V- and b-phase windings are reversed with respect to those of other phase windings. Thus, if three-phase voltages 120 degrees apart are input to the main transformer unit, then the phase angles between the main magnetic fluxes generated in any two adjacent magnetic circuits are equal to 30 degrees.

Abstract: A three phase saturating reactor is constructed of thin E and I shaped laminations that are interleaved to minimize the effects of air gaps. The laminations include apertures that are in alignment and four identical frame members are secured thereto by means of insulated bolts that pass through the apertures in the core and corresponding holes in the frame members. The taps of the electrical phase coils that encircle the legs of the core are of heavy conductors that are self-supporting. The saturating reactor design is such that the core is driven into saturation at a small percentage of the rated current of the reactor to rapidly develop a back EMF when in a motor starting circuit.

Abstract: One of a plurality of taps of at least one transformer is selected by choosing a predetermined plug to mate with a predetermined jack. The connection arrangement between each transformer and a corresponding jack is such that each pin of a respective jack is operatively connected to a predetermined transformer tap of the corresponding transformer whereby the corresponding taps of each of the transformers are connected to different corresponding pins for each of the corresponding jacks. Further, the starting tap of each transformer is operatively connected to the same corresponding pin of the jack corresponding to the transformer. A plurality of plugs, the number of plugs corresponding to one less than the number of pins of the jacks, is included whereby each plug has a plurality of mating pins corresponding to the pins of the jack. Each mating pin of each plug which corresponds to the pin of the starting tap is operatively connected to a first supply terminal.

Abstract: A rotating flux transformer having at least two magnetic cores, each in the form of a torus, with each magnetic core having poloidal and toroidal windings. The need for breaking the torus and bringing out leads from the poloidal winding is eliminated by passing each torus through the core window of the remaining torus, or tori. Each poloidal winding is shorted, with the toroidal winding, or windings, of the other magnetic core or cores, inducing an excitation voltage into each shorted poloidal winding which is 90.degree. out of phase with the voltage applied to the toroidal winding on the same magnetic core.

Abstract: A rotating flux transformer which includes a magnetic core having poloidal primary and secondary windings and toroidal primary and secondary windings. Quadrature flux is produced in the magnetic core by connecting one end of the poloidal primary winding to the center of the toroidal primary winding. The quadrature flux combines vectorially to produce a rotating induction vector in the magnetic core.

Abstract: Three-phase power susceptible of having different line to line input voltages in the wye and delta configurations is converted into a three-phase wye output, each phase of which has the same line to line voltage for all of the predetermined input voltages. A three-phase transformer has a secondary winding connected in a wye configuration. No switches are connected to the secondary winding. A primary winding of the transformer includes, for each phase, first and second coils, each having a single tap between a pair of end terminals. The terminals and taps are selectively connected in series with each other. The end terminals are selectively connected in parallel with each other. In certain of the situations all of first end terminals of first coils for each phase are connected to the line voltages. In others of the situations, predetermined first end terminals and taps of predetermined coils are connected to the line voltages and the first terminals and taps of other coils are connected to a neutral terminal.

Abstract: A connecting member for establishing delta circuits in a three-legged transformer includes a body formed from a mass of insulating material and having first, second and third pairs of opposing, radially extending connecting elements and electrically conductive members housed in the body and the pairs of electrical communication and for establishing a predetermined delta circuit when said pairs of connecting elements are electrically connected to the transformer terminals. Visual markings and/or window areas can be provided to permit visual determination of the first, second and third paths.

Abstract: A contact piece for providing conductive interconnection between the delta connection of the windings of a three-legged core transformer includes an insulative body having opposing vertical end surfaces in each of which a pair of end contacts is provided and an intermediate pair of opposing parallel horizontal surfaces in which a pair of opposing middle contacts are provided, the vertical separation between the pairs of end contacts and the pair of middle contacts being substantially equal. A transparent cover having horizontally separated and aligned apertures is also disclosed, the apertures being registered with one contact of each of the pairs of contacts.

Abstract: A three-phase transformer including tap changing apparatus for switching the turns ratio between the primary and secondary windings of a transformer. The tap changer comprises a cable operated mechanism for moving a movable contact carrier relative to three sets of fixed contacts disposed in a linear pattern, the movable contact carrier supporting three movable contacts for engagement with any pair of fixed contacts in each set of contacts, whereby a cable operated mechanism provides a high degree of flexibility in switch mounting position on a transformer.

Abstract: A combination transformer with common yoke core characterized by the combination of a main transformer and series transformers, which transformers have separate and complete core and coil assemblies with a common core leg or yoke to reduce the core size, weight and loss.

Abstract: A three-phase variable inductor is disclosed in which a fixed frame is formed by a plurality of laminar plates, the plates being rotated with respect to each other about a common axis. Within the frame, a Y network is located, the Y network being so constructed that the magnetic fields generated thereby during operation cancel out in the radial direction to prevent any net radial force from being exerted against a laminar movable reluctor that can be moved into and out of the frame and Y network. As a result of this construction, vibration is eliminated. Both the frame and the movable reluctor are made of iron and silicon, which reduced heat generation and increases efficiency.