Abstract: A transformer tank for a shell form transformer, for housing an active part of a three-phase transformer including transformer phases is provided. The tank includes a bottom tank part and a medium tank part comprising bottom plate and walls, a cover plate, reinforcing beams joined to the walls, interphase plates and stiffening supports for strengthening the cover plate. The interphase plates are to be arranged in a lower space of the tank, between adjacent transformer phases, extending from one wall to an opposite wall of the tank and coupled to the reinforcing beams. Each stiffening support is to be coupled to an interphase plate and extends in an upper space of the tank between the interphase plate and the cover plate, to cooperate with the cover plate. A three-phase shell form transformer and a method to assemble the transformer are also provided.

Abstract: Various magnetic thin film inductor structures are disclosed that include one or more magnetic thin film (MTF) materials. During operation, an electric field passes through one or more conductive windings which, in turn, generates a magnetic field for storing energy within these magnetic thin film inductor structures. The magnetic thin film (MTF) materials within these magnetic thin film inductor structures effectively attract magnetic flux lines of this magnetic field. As a result, any magnetic leakage resulting from the magnetic field generated by these magnetic thin film inductor structures onto nearby electrical, mechanical, and/or electro-mechanical devices is lessened when compared to magnetic leakage resulting from the magnetic field generated by other inductor structures not having the one or more MTF materials.

Abstract: A control device, for a power conversion device using a three-phase magnetic coupling reactor, includes: a first outer coil; a second outer coil; an inner coil disposed between the first outer coil and the second outer coil; and a core including a first outer core portion around which the first outer coil is wound, a second outer core portion around which the second outer coil is wound, and an inner core portion around which the inner coil is wound. Directions of magnetic fluxes generated in the first outer coil, the second outer coil, and the inner coil are opposite to each other in any combination. In a three-phase operation, the control device controls a value of the current flowing through the inner coil so as to approach values of the currents flowing through the first outer coil and the second outer coil.

Abstract: A fluid-cooled magnetic element. A plurality of coils is arranged in a non-toroidal configuration. Each coil may be a hollow cylinder, formed by winding a rectangular wire into a roll. The coils alternate with planer spacers. The coils may alternate in winding orientation, and the inner end of each coil may be connected, through a connection pin, to the inner end of an adjacent coil. Small gaps are formed between the coils and the spacers, e.g. as a result of each spacer having, on its two faces, a plurality of raised ribs, against which the coils abut. Cooling fluid flows through the gaps to cool the coils.

Abstract: Disclosed examples include integrated magnetic circuits for LLC resonant converters, including an inductor cell and multiple transformer cells with cores arranged in a stack structure. The individual transformer cells include primary and secondary windings extending around the transformer core structure, and a secondary transistor connected in series with the secondary winding. One or more windings are shaped near core stack gaps to reduce core and winding losses. The inductor cell includes an inductor winding extending around the inductor core structure to provide the inductor, and the capacitor. The inductor cell is arranged in the stack structure with the transformer cells to magnetically couple the transformer primary windings, the inductor winding and the transformer secondary windings in a single magnetic circuit to cancel cell to cell flux.

Abstract: A three-phase reactor includes: a central iron core; an outer peripheral iron core surrounding the central iron core; and at least three connecting units that magnetically connect the central iron core and the outer peripheral iron core to each other, in which each of the connecting units includes at least one connecting iron core, at least one coil wound around the connecting iron core, and at least one gap.

Abstract: A power transmission coil device includes a first helical coil having a first conductive wire forming a helical shape around an axis, and a second helical coil having a second conductive wire forming a helical shape around the axis, in which the first helical coil is electrically connected in parallel to the second helical coil, and the first conductive wire and the second conductive wire arranged along a direction of the axis.

Abstract: A multiphase DC/DC power converter includes a magnetic core having a plurality of core sections and defining a plurality of magnetic flux paths, and a plurality of winding including a plurality of transformer winding sets and a plurality of inductor windings. Each transformer winding set includes a primary winding and a secondary winding wound about at least one core section of the plurality of core sections. Each inductor winding is wound about another core section of the plurality of core sections. Magnetic flux generated by one transformer winding set of the plurality of transformer winding sets substantially cancels magnetic flux generated by at least one adjacent transformer winding set of the plurality of transformer winding sets. Magnetic flux generated by one inductor winding of the plurality of inductor windings substantially cancels magnetic flux generated by at least one adjacent inductor winding of the plurality of inductor windings.

Abstract: Disclosed herein is a choke coil including: a core composed of first and second legs, a first flat plate connecting an upper end portion of the first leg and that of the second leg, and a second flat plate connecting a lower end portion of the first leg and that of the second leg; a primary coil wound around the first leg; and a secondary coil wound around the second leg, wherein a width of at least any one of the first flat plate and the second flat plate is greater than widths of the first leg and the second leg.

Abstract: A fault current limiter is provided that comprises a magnetically saturable core. The first core includes a first leg, a second leg, with a first AC coil wound on the second leg, a third leg, with a second AC coil wound around the third leg, the first and second AC coils being wound in series and connected to a first phase AC source, and a fourth leg. The first magnetic biasing unit is arranged to produce a first closed magnetic circuit in the first leg and the second leg that has a first flux direction, and the second coil is arranged to produce a second closed magnetic circuit in the fourth leg and the third leg that has a second flux direction, wherein the first flux direction opposes the second flux direction. The first and second AC coils are arranged to produce a first closed AC magnetic circuit in the second and third legs in an AC flux direction that alternates with each AC half-cycle.

Abstract: A transformer includes a magnetic core, a primary winding, and a plurality of secondary windings. The magnetic core has an axial and a radial direction. The primary winding includes a plurality of winding sections and at least one connecting section. The winding sections are arranged along the axial direction. The connecting section is connected between the two adjacent winding sections. Each of the winding sections includes a plurality of primary winding layers and pull-out portions. The primary winding layers surround the magnetic core and are arranged along the radial direction. One pull-out portion connects two primary winding layers adjacent to the pull-out portion. Part of normal projections of the primary winding layers on a surface of the magnetic core are located between normal projections of the pull-out portions on the surface of the magnetic core. The secondary windings surround the primary winding.

Abstract: The invention relates to a coupling device (4) for four phases of a multi-phase converter (2). Said coupling device (4) includes four coupling modules (6, 8, 12, 14), each of which encompasses four parallel through-holes. At least one section of a conductor loop (18, 20, 22, 24) for a phase. At least one section of a conductor loop (18, 20, 22, 24) for a phase penetrates a through-hole of a coupling module (6, 8, 12, 14), sections of conductor loops (18, 20, 22, 24) for at least two phases penetrating all four through-holes of a coupling module (6, 8, 12, 14).

Abstract: An electrical generator including a ring shaped coil and a plurality of magnets attached to the ring shaped coil. The magnets may be operatively connected to a power supply. A controller may be connected to the power supply to turn the magnets on and off. The magnets may be turned on and off sequentially around the ring shaped coil to generate electricity.

Abstract: A power supply device comprising an advanced harmonic current quashing (AHQ) and current pulse multiplier (CPM) (AHQ/CPM) three-phase transformer having: a primary winding placed around a magnetic core and having three primary winding input leads to connect a three phase power supply; and a plurality of secondary windings placed around the magnetic core in a predetermined winding turns configuration to generate a plurality of three phase outputs, where each three phase output of the plurality of three phase outputs has a different phase angle from all other three phase outputs, with each unique phase angle associated with a three phase output of a corresponding secondary winding being determined based on the winding turns configuration utilized for the corresponding secondary winding. A variable frequency drive (VFD) having 3N converters/inverters coupled to the secondary windings outputs exhibit substantially reduced harmonic currents and a current pulse number of greater than 6N.

Abstract: An energy-saving device (1) inserted between a three-phase power supply (A) and a three-phase load (L), includes a three-phase electrical transformer (10), each phase of which includes a transformation assembly (11) with a primary winding (2) connected at a first end (5) to one phase of the power supply (A) and electromagnetically coupled to a secondary winding (3) connected at its second end (S1) to one phase of the load (L). The device (1) involves the second ends (6) of the primary windings (2) in each of the transformation assemblies (11), lying opposite the first ends (5), being electrically connected to one another by a first switch (4). The device (1) also involves each of the secondary windings (3) being connected in parallel to a second switch (7) for enabling or disabling the operation of the energy-saving device (1) between the power source (A) and the load (L).

Abstract: A high frequency transformer with high conversion efficiency is provided. The high frequency transformer includes a first coil assembly 1 formed from a single flat wire, with first coils 1A that are configured by winding the flat wire edgewise plural times and that are formed at specific intervals, and a second coil assembly 2 formed from a single flat wire, with second coils 2A that are configured by winding the flat wire edgewise plural times and that are formed at specific intervals.

Abstract: An integrated magnetic device for low harmonics three-phase front-end (1) comprising three magnetic sub-assemblies (30), wherein each magnetic sub-assembly (30) comprises a magnetic core without air-gaps, three or more wound limbs and at least five windings, three current inputs connectable to a three-phase power grid (100), at least nine current outputs, three for each current inputs, said current outputs being galvanically connected to said three current inputs and connectable to a load (200). The integrated magnetic device is designed for a low harmonics three-phase bidirectional front-end and also for AC/DC rectifier and DC/AC power inverters. Its use enables reduction of the harmonics of the currents absorbed or injected to three-phase power line by using only one device which integrates a splitter and an inductor function. Compared to known solutions, cost, material and dimensions of the integrated magnetic device are reduced.

Abstract: The present invention provides a hybrid transformer. In a transformer comprising a primary core and a secondary coil, the hybrid transformer includes a core with a 1st leg, a 2nd leg, and a 3rd leg; and a secondary coil with a 1st winding, a 2nd winding and a 3rd winding, which are wound zigzag on said 1st leg, said 2nd leg, and said 3rd leg. Two types of windings selected from the group consisting of said 1st winding, said 2nd winding and said 3rd winding are wound alternatively on said 1st leg, said 2nd leg, and said 3rd leg, respectively. However, the two types of windings wound on said 1st leg, said 2nd leg, and said 3rd leg, respectively, are wound in an overlapping manner around said core in the winding order.

Abstract: A coupled inductor array includes a magnetic core and N windings, where N is an integer greater than one. The magnetic core has opposing first and second sides, and a linear separation distance between the first and second sides defines a length of the magnetic core. The N windings pass at least partially through the magnetic core in the lengthwise direction, and each of the N windings forms a loop in the magnetic core around a respective winding axis. Each winding axis is generally perpendicular to the lengthwise direction and parallel to but offset from each other winding axis. Each winding has opposing first and second ends extending towards at least the first and second sides of the magnetic core, respectively. One possible application of the coupled inductor array is in a multi-phase switching power converter.

Abstract: A dual-input nine-phase autotransformer converts first and second three-phase AC inputs to a nine-phase AC output. The autotransformer includes input terminals for connection to a first three-phase AC input and a second three-phase AC input smaller than the first three-phase AC input. The autotransformer includes a first plurality of coils, a second plurality, and a third plurality of coils wound on respective phase legs of the autotransformer. The autotransformer includes a plurality of output terminals for providing a plurality of AC output voltages, and a plurality of internal terminals for connecting the first, second, and third plurality of coils in a configuration that provides a 40° phase shift in the AC outputs provided by the dual-input nine-phase autotransformer.

Abstract: An AC transformer having a cylindrical core configurable for single or polyphase power input and/or output transformer applications. The transformer core structure is capable of being configured to provide for single or polyphase inputs or outputs by varying the transformer primary and secondary winding configuratons. A polyphase input configuration can be utilized in polyphase output transformers, such as for variable frequency drive (VFD) applications. Additional methods for winding transformer cores minimize the quantity of core winding wire necessary for transformer manufacture.

Abstract: A tap-switching autotransformer for regulating the voltage supplied to a facility includes an electronics sub-assembly for controlling switching of the taps. The electronics sub-assembly and the windings are contained in a housing from which the electronics sub-assembly may be removed for repair or replacement. The electronics sub-assembly is adapted to enable an electronically actuated switch to short-circuit two of the taps. A mechanical switch enables a separate short-circuit to be maintained between the taps to enable the electronics sub-assembly to be safely removed from the housing.

Abstract: A multi-parallel magnetic-filed cancellation type transformer includes a plurality of coils which generate magnetic flux during energization and a core having a plurality of magnetic leg portions on which the coils are wound, and bases for fixing the magnetic leg portions. The plurality of coils are wound on the magnetic leg portions in such a manner that the magnetic flux generated from the coils are formed in the directions opposite to each other. A plurality of closed magnetic circuits of the magnetic flux are formed at the magnetic leg portions and the bases. The magnetic resistance of the closed magnetic circuits is homogeneous. Accordingly, the transformer can reduce the size thereof, and prevent the deterioration of electric power conversion efficiency.

Abstract: A versatile distribution transformer having an electromagnetic transformer and a power electronic module is provided. A pocket having connectors electrically connected to at least one winding structure of the electromagnetic transformer is mounted above the electromagnetic transformer. The power electronic module is removably mounted in a cavity of the pocket. The power electronic module includes a plurality of semiconductor switching devices and a plurality of connectors adapted to slidably engage the connectors of the pocket. The power electronic module is movable between a removed position, wherein the power electronic module is located outside the pocket, and an installed position, wherein the power electronic module is disposed in the cavity of the pocket and the connectors of the power electronic module engage the connectors of the pocket so as to electrically connect the power electronic module to the at least one winding structure.

Abstract: A method for powering a magnetic coupler, in which: a) each winding of a first magnetic elementary cell is powered such as to produce a magnetizing flux in a bar of the first cell which is joined with a second cell, the fundamental component of which has an angular offset xi; and b) powering each winding of the second cell such as to produce a magnetizing flux in the bar of the second cell which is joined with the first cell, the fundamental component of which has an angular offset xj. The absolute value of the difference between the angular offsets xi and xj is greater than or equal to (I) rad.

Abstract: Different configurations of transient voltage quashing (TQ) transformers, harmonic current quashing (HQ) transformers, and transient voltage and harmonic current quashing (THQ) transformers include one or more of: a tertiary winding radially placed between the primary and secondary windings, with a surge suppressors coupled thereto, which quashes transient voltages in the transformer and any output device attached to output leads of the tertiary or secondary windings; and an arrangement of the secondary windings, separated by at least a second type intra-winding insulation, into one or a plurality of output winding groups, each used to provide power to N serially-connected output devices that exhibit known/expected output voltage characteristics.

Abstract: The present invention relates to a power quality improvement device. The power quality improvement device is provided in the form of an autotransformer which comprises an iron core having first, second and third legs, and first, second and third coils which are wound in a zigzag fashion around said first, second and third legs. At least two coils selected from the group that includes said first, second and third coils, alternatively wound around each of said first, second and third legs, are over-lappingly wound around the core in a winding sequence.

Abstract: The present invention provides a hybrid transformer. In a transformer comprising a primary core and a secondary coil, the hybrid transformer includes a core with a 1st leg, a 2nd leg, and a 3rd leg; and a secondary coil with a 1st winding, a 2nd winding and a 3rd winding, which are wound zigzag on said 1st leg, said 2nd leg, and said 3rd leg. Two types of windings selected from the group consisting of said 1st winding, said 2nd winding and said 3rd winding are wound alternatively on said 1st leg, said 2nd leg, and said 3rd leg, respectively. However, the two types of windings wound on said 1st leg, said 2nd leg, and said 3rd leg, respectively, are wound in an overlapping manner around said core in the winding order.

Abstract: In a three phase wound transformer core three frames are connected in triangular fashion, each frame being made of multiple rings wound in off-set fashion on a common axis.

Abstract: A transformer having high and low voltage coils mounted to legs of a core is provided. Each low voltage coil includes conductor sheeting having opposing first and second ends and opposing first and second side edges. A pair of coil bus bars is provided for each low voltage coil. Each coil bus bar has first and second portions, wherein the first portion has a width that is more than one and a half times greater than a width of the second portion. Each coil bus bar is secured to the conductor sheeting of its low voltage coil such that the first portion of the coil bus bar is disposed at the first side edge of the conductor sheeting and the second portion of the coil bus bar is disposed at the second side edge of the conductor sheeting.

Abstract: A method for powering a magnetic coupler, in which: a) each winding of a first magnetic elementary cell is powered such as to produce a magnetizing flux in a bar of the first cell which is joined with a second cell, the fundamental component of which has an angular offset xi; and b) powering each winding of the second cell such as to produce a magnetizing flux in the bar of the second cell which is joined with the first cell, the fundamental component of which has an angular offset xj. The absolute value of the difference between the angular offsets xi and xj is greater than or equal to (I) rad.

Abstract: A multi-parallel magnetic-filed cancellation type transformer includes a plurality of coils which generate magnetic flux during energization and a core having a plurality of magnetic leg portions on which the coils are wound, and bases for fixing the magnetic leg portions. The plurality of coils are wound on the magnetic leg portions in such a manner that the magnetic flux generated from the coils are formed in the directions opposite to each other. A plurality of closed magnetic circuits of the magnetic flux are formed at the magnetic leg portions and the bases. The magnetic resistance of the closed magnetic circuits is homogeneous. Accordingly, the transformer can reduce the size thereof, and prevent the deterioration of electric power conversion efficiency.

Abstract: A transformer includes a zigzag transformer comprising first, second and third magnetic cores. The transformer further includes an auxiliary winding set comprising respective pairs of series-connected windings on respective pairs of the first, second and third magnetic cores, the pairs of series-connected windings having respective first terminals connected to respective AC phases of the zigzag autotransformer and respective second terminals configured to provide respective AC output phases.

Abstract: Various embodiments of multi-phase transformers are disclosed. Exemplary transformer includes primary windings, secondary windings and third windings. Primary windings, secondary windings and third windings may include sub windings coupled to form functions. Primary windings are coupled at ends to form a delta configurations. Secondary windings are coupled to primary windings. Third windings are coupled to primary windings and secondary windings. Secondary windings and the third windings are magnetically coupled to primary windings. The outputs at second ends of third windings are greater than the outputs at the second ends of secondary windings. In some embodiments, the outputs at adjacent second ends of the third windings are substantially equal. In some embodiments, the phase angle difference of outputs at adjacent second ends of third windings are substantially equal. In some embodiments, the phase angle difference of outputs at adjacent second ends of secondary windings are substantial equal.

Abstract: Various embodiments of multi-phase transformers are disclosed. For example, a transformer includes primary windings, secondary windings and third windings. Primary windings, secondary windings and third windings may include sub windings coupled to form junctions. Primary windings are coupled at ends to form a delta configuration. Secondary windings are coupled to primary windings. Third windings are coupled to primary windings and secondary windings. Secondary windings and the third windings may be magnetically coupled to primary windings. The outputs at second ends of third windings are greater than the outputs at the second ends of secondary windings. In some embodiments, the outputs at adjacent second ends of the third windings are substantially equal. In other embodiments, a phase angle difference of outputs at adjacent second ends of third windings is substantially equal. In some embodiments, the phase angle difference of outputs at adjacent second ends of secondary windings is substantially equal.

Abstract: The invention is directed to a transformer and a method of manufacturing the same. The transformer has high and low voltage coils mounted to legs of a core. Each low voltage coil includes conductor sheeting having opposing first and second ends and opposing first and second side edges. A pair of coil bus bars is provided for each low voltage coil. Each coil bus bar has first and second portions, wherein the first portion has a width that is more than one and a half times greater than a width of the second portion. Each coil bus bar is secured to the conductor sheeting of its low voltage coil such that the first portion of the coil bus bar is disposed at the first side edge of the conductor sheeting and the second portion of the coil bus bar is disposed at the second side edge of the conductor sheeting.

Abstract: A polygon connected three-phase autotransformer using six windings per phase provides a reduced power rating nine-phase power source suitable for 18-pulse AC to DC power converters. The windings are selected and connected in a manner that controls harmonic currents and minimizes total kVA rating. When the autotransformer is used to power a nine-phase AC to DC converter its kVA rating is typically less than 48% of the DC load kW. Additional isolated windings can provide means for the invention to operate as an efficient double-wound transformer.

Abstract: Various embodiments of multi-phase transformers are disclosed. Exemplary transformer includes primary windings, secondary windings and third windings. Primary windings, secondary windings and third windings may include sub windings coupled to form junctions. Primary windings are coupled at ends to form a delta configurations. Secondary windings are coupled to primary windings. Third windings are coupled to primary windings and secondary windings. Secondary windings and the third windings are magnetically coupled to primary windings. The outputs at second ends of third windings are greater than the outputs at the second ends of secondary windings. In some embodiments, the outputs at adjacent second ends of the third windings are substantially equal. In some embodiments, the phase angle difference of outputs at adjacent second ends of third windings are substantially equal. In some embodiments, the phase angle difference of outputs at adjacent second ends of secondary windings are substantially equal.

Abstract: Various embodiments of multi-phase transformers are disclosed. For example, a transformer includes primary windings, secondary windings and third windings. Primary windings, secondary windings and third windings may include sub windings coupled to form junctions. Primary windings are coupled at ends to form a delta configuration. Secondary windings are coupled to primary windings. Third windings are coupled to primary windings and secondary windings. Secondary windings and the third windings may be magnetically coupled to primary windings. The outputs at second ends of third windings are greater than the outputs at the second ends of secondary windings. In some embodiments, the outputs at adjacent second ends of the third windings are substantially equal. In other embodiments, a phase angle difference of outputs at adjacent second ends of third windings is substantially equal. In some embodiments, the phase angle difference of outputs at adjacent second ends of secondary windings is substantially equal.

Abstract: A zigzag autotransformer includes a zigzag transformer including first, second and third magnetic cores and an auxiliary winding set including respective pairs of series-connected windings on respective pairs of the first, second and third magnetic cores, the pairs of series-connected windings having respective first terminals connected to respective AC input phase terminals of the zigzag autotransformer and respective second terminals configured to provide respective AC output phases.

Abstract: An inductor array that includes a plurality of inductors where adjacent inductors share a core piece and thus a flux path to reduce the size and weight of the array. In one embodiment, the shared core pieces are formed as back-to-back U-shaped members defining an indented region at the center of the core piece. In another embodiment, a plurality of small block-shaped center core pieces in each inductor defines a plurality of gaps therebetween.

Abstract: A torque detecting device includes an elastic member disposed between an input shaft and an output shaft of a torque transmitting apparatus, first and second resolvers detecting rotational angles of the elastic member at sides of the input shaft and the output shaft. The first resolver includes a first excitation winding coil and a first output winding coil, and the second resolver includes a second excitation winding coil and a second output winding coil. The first and second excitation winding coils are connected to a ground, and the first and second output winding coils are connected to the other ground.

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: A 3-D spiral stacked inductor is provided having a substrate with a plurality of turns in a plurality of levels wherein the number of levels increases from an inner turn to the outer turn of the inductor. First and second connecting portions are respectively connected to an inner turn and an outermost turn, and dielectric material contains the first and second connecting portions and the plurality of turns over the substrate.

Abstract: An electrical transformer is disclosed. The electrical transformer comprises a central axis, a first modular section, and a second modular section. The first modular section is positioned about the central axis and comprises a first support, a first winding of a conductive element, and a first insulating material. The first winding of a conductive element is located about the first support. The first insulating material covers a portion of the first modular section. The second modular section is axially aligned with the first modular section and electrically connected to the first modular section. The second modular section comprises a second support, a second winding of a conductive element, and a second insulating material. The second winding of a conductive element is located about the second support. The second insulating material covers a portion of the second modular section.

Abstract: A high frequency power amplifying device has two amplifying lines. Each amplifying line has a configuration in which a plurality of amplifying stages are connected in cascade having two source voltage terminals, of which one is connected to the first amplifying stage of one amplifying line and to the remaining amplifying stages of the other amplifying line, and the other, to the first amplifying stage of the latter amplifying line and to the remaining amplifying stages of the former amplifying line. An air core coil with a low D.C. resistance, formed by spirally winding a copper wire of about 0.1 mm in diameter, is connected in series between the final amplifying stage of each amplifying line and the source voltage terminal. Since there is no signal leak in each amplifying line from the final amplifying stage to the first amplifying stage and the D.C. resistance of the air core coil is low, oscillation margin can be improved.

Abstract: A winding structure for a transformer has a first support having a central axis, and a second support also having a central axis. The second support is positioned having its central axis generally in-line with the central axis of the first support. The winding structure also has a winding which is wrapped around at least a portion of the first and second supports. The supports are tubular and are provided for at least supporting the winding. A method of making the transformer includes the steps of providing a mounting apparatus, and mounting a first support having a central on the mounting apparatus. The method also includes mounting a second support having a central axis on the mounting apparatus, wherein the second support is mounted on the mounting apparatus with its central axis mounted generally in-line with the central axis of the first support. In addition, the method includes winding a conductor around at least a portion of the first and second supports to form a winding.

Abstract: A ballast circuit includes an equalizer transformer for equalizing current between two or more lamps operated in parallel, combined on one core with a choke. In a 2-lamp embodiment, four windings are provided on one main core. The first and second are closely coupled and have N turns each, each connected separately to one of the lamps. A third and fourth winding are loosely coupled with respect to each other, and are arranged symmetrically about the first and second windings on the main core. These latter windings may be connected in series or in parallel to be an inductive impedance in the ballast circuit.

Abstract: A transformer for a cycloconverter includes three single-phase transformers connected into a three-phase configuration. Each of the single-phase transformers includes a two-legged core, primary windings wound on at least one of legs of the two-legged core, and twelve secondary windings wound on at least one of the legs of the two-legged core. The secondary windings are connected to positive group converters and negative group converters of a three-phase output circulating current type cycloconverter composed of three single-phase output circulating current type cycloconverters connected in a three-phase configuration. Each of the single-phase output circulating current type cycloconverters includes two positive group converters and two negative group converters arranged in a twelve-pulse bridge configuration.

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.