Abstract: An energy transfer apparatus is developed for reducing a conductivity electromagnetic interference and manufacturing method. The energy transfer apparatus comprises a core, an input winding, an output winding, a supply voltage and a supply winding. The supply winding includes a shielding winding and an auxiliary winding. The input winding receives an input voltage for outputting the output voltage through the core and the output winding. The shielding winding and the auxiliary winding generate the supply voltage through the core. By setting of wire size and winding turns of the shielding winding, the conductivity electromagnetic interference is reduced for stabilizing an electric potential between an input-grounding terminal and an output-grounding terminal of the energy transfer apparatus.

Abstract: A transformer having adjustable leakage inductance includes a primary winding coil, a secondary winding coil, a bobbin and a magnetic core assembly. The bobbin includes a winding section for winding the primary winding coil and the secondary winding coil thereon, wherein the bobbin further includes a channel therein. The magnetic core assembly is partially embedded into the channel of the first bobbin. The primary winding coil and the secondary winding coil are partially overlapped with each other and wound around the winding section of the bobbin to be defined as an overlap region. The region where the primary winding coil and the secondary winding coil are not overlapped with each other is defined as a non-overlap region. The leakage inductance of the transformer is adjusted according to an overlap ratio of the overlap region to the sum of the overlap region and the non-overlap region.

Abstract: A Winding for high voltage transformer having a predetermined number of spaced winding groups joined to form a single winding transformer, each spaced winding group being solenoid wound from a predetermined number of turns. A method of forming the winding and a transformer including the winding are also disclosed.

Abstract: An energy transfer element having an energy transfer element input winding and an energy transfer element output winding. In one aspect, the energy transfer element input winding is capacitively coupled to the energy transfer element output winding. The energy transfer element is capacitively coupled to electrical earth. One or more additional windings are introduced as part of the energy transfer element. The one or more additional windings substantially reduce capacitive displacement current between the energy transfer element input winding and energy transfer element output winding by balancing the relative electrostatic fields generated between these windings and/or between the energy transfer element and electrical earth by canceling the electrostatic fields generated by all windings within the energy transfer element relative to electrical earth through the selection of the physical position and number of turns in the additional windings.

Abstract: An electric machine comprises a core (10) of magnetic material and a first insulating layer (14) of a solid electrically insulating material surrounding the core. A high-voltage winding (17) in the form of an electric conductor is wound around a first part (16) of the first insulating layer and a field-equalizing member (19) is arranged around a second part (18) of the first insulation layer. Further, a second insulating layer (20) of a solid electrically insulating material surrounds the high-voltage winding and the field-equalizing member. The field-equalizing member comprises at least one first sub-member in the form of a winding (27, 28, 37, 38), and an electric cable conductor (31) is intended to be connected to the high-voltage winding at the field-equalizing member.

Abstract: Toroidal transformer and inductor configurations are described that allow for greater heat transfer away from internal device components. The inventive transformer allows for higher thermal and electrical efficiency, as well as for more efficient use of expensive components, such as copper wire. In one embodiment, a toroidal transformer provides access for cooling air by forming the primary winding from a single layer of thick wire and a secondary winding of few turns such that most of the primary winding is exposed to air flow. In another embodiment, a heat sink is positioned between the core and primary windings to conduct heat away from the transformer.

Abstract: An electromagnetic device and a high-voltage generating device which are thin with improved characteristics includes a magnetic core of a cylindrical form of a ferrite material having a high intrinsic resistance. A winding is provided by winding a flat rectangular wire conductor in an edge-wise winding directly on substantially the entire length of the magnetic core. As an insulator, such as a coil bobbin, is not needed between the flat rectangular wire conductor and the magnetic core, the winding can be decreased in the overall size or thickness thus contributing to the reduction in dimension of the electromagnetic device. Also, as its flat rectangular wire conductor is wound directly on the magnetic core, the winding can be minimized in the length and thus the overall resistance.

Abstract: A full wave DC/DC converter magnetically integrates into the transformer assembly the functions of the resonant inductor, magnetizing inductor and the output filter inductor. The primary and the secondary windings are assembled on a gapped center leg of an E-core, while two output filter windings with an equal number of turns are assembled on gapped left and gapped opposed side legs of the E-core. The length of the gaps in the side legs is selected so that the DC current does not saturate the side legs. The two filter windings are connected in series and are oppositely polarized so that the voltages induced in these windings by the primary winding flux cancel each other.

Abstract: An electronic component with inductive and capacitive properties has a core carrying at least one pair of conducting electrodes. The electrodes are wound round the core alternating along the length of the core providing inductivity to the component. First and second electrodes face each other on opposing surfaces of the core providing capacity to the component. To provide an electronic component with high inductivity and capacity, the core is made of material featuring high dielectric constant and high permeability.

Abstract: In a main conductor for a capacitively controlled high-voltage winding composed of pancake coils for transformers, in which the main conductor for the load current is realized as a twisted conductor, and in which a control conductor is provided which is spatially arranged inside the twisted conductor and is electrically separated from the twisted conductor, the main conductor consists of two twisted conductors (1, 2) that are electrically separated from each other. The control conductor consists of several flat copper conductors (7) covered by an insulating sheath (7a), and the copper conductors (7) are fastened to one of the twisted conductors (1, 2).

Abstract: A transformer for a lamp system. A first spindle comprises a first hollow portion. A second spindle comprises a second hollow portion and is arranged in parallel with the first spindle. A first coil is wound around the first spindle. Second coils are wound around the second spindle. The number of second coils is even. Windings of the second coils are approximately equal. The core module is disposed in the first and second hollow portions.

Abstract: The winding of matrix transformers having multiple turn primary windings is made much easier, and the resulting transformer is much more consistent, if a “cellular” insert having a plurality of through holes is placed through each trough hole of the matrix transformer. Preferably, there is one hole in the cellular insert for each wire, though two or more wires can be placed in each hole. In one embodiment, insulating cellular inserts are placed through the entire length of the cellular transformer to guide and locate the primary windings. In another embodiment, each element of the cellular transformer has cellular inserts, and the elements are coupled together. In another embodiment, the cellular insert is a conductor and is part of the secondary circuit.

Abstract: An electrical device operating on the principle of induction, such as a transformer. The device employs High Temperature Superconductors to build pancake coils having a very low height to diameter ratio. These pancake coils are placed around ferromagnetic core legs as in a conventional transformer. In multiphase applications, the low height to diameter ratio of the pancake coils causes the transformer to become quite wide. The present invention proposes overlapping the adjacent pancake coils in a multiphase induction device to reduce the width. A specific example of a 3-phase power transformer is presented.

Abstract: The invention relates to a device for the inductive transmission of electrical power, comprising a power line which is situated on the primary side of said device and which consists of two wires which are guided in a parallel manner relative to each other. Power can be drawn from line by at least one mobile consumer, which is situated on the secondary side, by means of inductive coupling. Said device is provided with a data line which is situated on the primary side for the additional inductive transmission of data to and/or from the consumer. Said data line consists of two wires which are guided in a parallel manner relative to each other. Each of the data line wires is arranged adjacent to one of the two power line wires and in a manner that is symmetrical to a plane. The cross section of the conductor of the adjacent wire of the energy line is also symmetrical relative to the plane.

Abstract: The present invention relates to a power transformer/inductor comprising at least one winding. The windings are designed by means of a high-voltage cable, comprising an electric conductor, and around the conductor there is arranged a first semiconducting layer, around the first semiconducting layer there is arranged an insulating layer and around the insulating layer there is arranged a second semiconducting layer. The second semiconducting layer is earthed at or in the vicinity of both ends (261, 262; 281, 282) of each winding and furthermore one point between both ends (261, 262; 281, 282) is directly earthed.

Abstract: A magnetic core has a toroidal configuration, formed by winding an iron-based amorphous metal ribbon. Thereafter the core is heat-treated to achieve a linear B-H characteristic. Advantageously, the linear B-H characteristic does not change with the level of magnetic fields applied and the frequency utilized. With such properties, the core is especially suited for use in a current transformer.

Abstract: A magnetic device is provided that may be employed with surface mount technology. In an advantageous embodiment, the magnetic device includes a magnetic core having a magnetic core half and a springable winding positioned about at least a portion of the magnetic core half. The springable winding includes a terminus biased against the magnetic core half.

Abstract: An inductor module includes a common inductor core, and first and second inductor windings. Each of the first and second inductor windings has an input end, an output end, and an inductor winding section disposed between the input and output ends. The inductor winding sections are wound on the common inductor core such that the distance between the input end of the first inductor winding and the output end of the second inductor winding is larger than the distance between the output end of the first inductor winding and the input end of the second inductor winding. The output end of the first inductor winding is free of an electrical connection with the input end of the second inductor winding.

Abstract: The present invention is directed to a method of installing transformer winding coils, including the steps of: providing a transforming including a magnetic core assembly, a primary winding coil, a secondary winding coil, a winding frame, and an enclosure, wherein the primary winding coil and the secondary winding coil are respectively wounded around the winding frame; wrapping the portions of the winding coils wounded around the winding frame with a tape and leading out a plurality of winding outlets from the winding frame; positioning the magnetic core assembly and the winding frame fixedly within the enclosure; and directly securing the winding outlets to a printed circuit board such that the transformer can be electrically connected to the printed circuit board.

Abstract: In a push-pull switching circuit for a low-voltage, large-current application, it is desired to decrease the resistance of a transformer and of its peripheral circuit. For this purpose, a first coil (35) is wound around a first winding core (31) with respect to as a winding start position a side surface of the first winding core (31) which does not oppose a second winding core (31). A second coil (35) is wound around the second winding core (31), with respect to as a winding start position a side surface of the second winding core (31) which opposes the first winding core (31), in the same winding direction as that of the first coil (35) and in a feeding direction different from that of the first coil (35). The first and second coils are electrically connected in series with each other.

Abstract: The invention relates to a bushing-type transformer (1) comprising a conductive element (5) forming the primary conductor, supporting a flat contact surface (7) on one end thereof and a plug-in contact element (8) on the other end thereof, whereby the plug-in contact element (8) is embodied in a rotationally symmetrical manner and the rotational axis is arranged parallel to the flat contact surface (7). Said transformer also comprises a secondary winding (6) which surrounds the conductive piece (5) in an annular manner. The conductive element (5) extends in a linear manner and the plug-in contact element (8) is arranged on the surface area of the conductive piece (5).

Abstract: A transformer circuit arrangement has a first transformer (201) with a first lower limit frequency (fu1) and a first upper limit frequency (fo1), and a second transformer (202) with a second lower limit frequency (fu2) and a second upper limit frequency (fo2), whereby the first lower limit frequency (fu1) is smaller than the second upper limit frequency (fu2), and the second upper limit frequency (fo2) is greater than the first upper limit frequency (fo1), the second lower limit frequency (fu2) is preferably not greater or smaller than the first upper limit frequency (fo1) by a factor of 10, at least one input (103, 104) of the first transformer is electrically connected to an input (209, 210) of the second transformer, and at least one output (205, 206) of the first transformer is connected to an output (107, 108) of the second transformer, and the transformer circuit arrangement has a band pass behaviour with a lower overall limit frequency (fuges) and an upper overall limit frequency (foges), whereby the l

Abstract: This transformer has improved cooling properties resulting in enhanced production of induced current.

Abstract: The present invention provides a high peak current, low duty cycle, pulse type transformer with two methods of increasing the coupling coefficient between the primary and secondary windings. The first method provides an increased coupling coefficient for a pulse type transformer of a coreless design by increasing the number of secondary turns in proximity to a number of primary turns by providing multiple primary windings and multiple secondary windings configured in layers or winding bays in an alternating secondary, primary, secondary, primary configuration. The second method provides an increased coupling coefficient for a pulse type transformer with a magnetic core that utilizes a non-uniform cross-sectional area along the magnetic path where the cross-sectional area is increased within the primary and secondary windings.

Abstract: The current technology involved with overlaying any type of digital subscriber loop (xDSL) service with plain old telephone service (POTS) makes use of two separate transformers, one for POTS and another for xDSL. This invention provides a transformer which combines the POTS transformer and the xDSL transformer into one transformer. This considerably reduces the weight volume and cost of the overlaid POTS and xDSL circuits. In combining the two transformers the magnetic coupling between any one of the windings used for POTS and any one of those used for xDSL must remain weak despite their close proximity. In addition, any two windings of the same type of service, either POTS or xDSL, must remain strongly coupled. This is achieved by choosing a special geometric form for the core and choosing strategic locations for the windings. A portion of the core is dedicated to serve as a shunt for each component of the magnetic field produced by the windings.

Abstract: In a transformer assembly formed by using a plurality of transformers each formed by winding a primary coil and a secondary coil around a winding core, one terminal and the other terminal of the primary coil are arranged on opposite sides of the winding core, one terminal and the other terminal of the secondary coil are arranged on opposite sides of the winding core, and N transformers in which the coils and the terminals are laid out are arrayed in the lead-out direction of the terminals of the primary coil while M transformers in which the coils and the terminals are laid out are arrayed in the lead-out direction of the terminals of the secondary coil so as to make a line which connects one terminal and the other terminal of the primary coil cross a line which connects one terminal and the other terminal of the secondary coil.

Abstract: A high voltage transformer includes a core, an output terminal, and an insulation member. The core is surrounded by coils to boost an alternating current voltage, and is grounded. The output terminal outputs the voltage boosted by the plurality of coils. The insulation member is disposed between the output terminal and the core.

Abstract: A dual transformer design, each transformer having at least a primary winding and a secondary winding disposed on a core means, wherein the core means is circumferentially disposed about an inner housing means, and the whole structure located within an outer housing. The primary winding of one transformer of said pair of transformers is electrically coupled to the primary winding of the other in a manner such as to cause induced eddy currents from one transformer to be of a magnitude and direction so as to substantially cancel the induced eddy currents from the other transformer.

Abstract: An oil-filled pole-mounted distribution transformer comprises a tank housing a transformer core-coil assembly immersed in cooling oil. The tank is made of a corrosion-proof composite material and a radiator is provided for cooling the oil. The radiator is external to the tank and has a hot oil inlet and a cool oil outlet located at different levels into the tank for causing a natural circulation of oil through the radiator by thermal siphoning.

Abstract: An isolating coupling arrangement couples signals in both directions via a transformer between first and second (or more) units each having differential signal transmit buffers and receivers. A diode bridge and capacitor produce an isolated power supply voltage for the second unit from signals coupled from the first unit via the transformer. The diode bridge can use intrinsic diodes of CMOS output circuits of the transmit buffers, which can be controlled synchronously using a phase locked loop responsive to signals coupled from the first unit via the transformer. A supply voltage for the first unit can be increased to compensate for voltage drops of the diode bridge on start-up prior to the synchronous operation. A resistor in parallel with a diode of the bridge provides an asymmetrical load to create a DC component of transformer magnetizing current to eliminate oscillations during signal gaps.

Abstract: A high power static electromagnetic device with a flux path, a main winding and one or more regulation windings surrounding portions of the flux path. A control device is coupled to the flux path for selectively admitting the flux therein. In an exemplary embodiment, multiple flux paths are selectively turned on and off for including and excluding the regulation windings from the circuit. The windings may be formed of a magnetically permeable, field-confining insulating cable.

Abstract: An integrated magnetic assembly that allows the primary and secondary windings of a transformer and a separate inductor winding to be integrated on a unitary magnetic structure is disclosed. The unitary magnetic structure includes first, second, and third legs that are physically connected and magnetically coupled. The primary and secondary windings of the transformer can be formed on the third leg of the unitary magnetic structure. Alternatively, the primary and secondary windings can be split between the first and second legs. Thus, the primary winding includes first and second primary windings disposed on the first and second legs and the secondary winding includes first and second secondary windings disposed on the first and second legs. The inductor winding may also be formed either on the third leg or it may split into first and second inductor windings and disposed on the first and second legs. In addition, one or more legs may include an energy storage component such as an air gap.

Abstract: The invention relates to a device for the inductive transmission of electrical power, comprising a power line which is situated on the primary side of said device and which consists of two wires which are guided in a parallel manner relative to each other. Power can be drawn from line by at least one mobile consumer, which is situated on the secondary side, by means of inductive coupling. Said device is provided with a data line which is situated on the primary side for the additional inductive transmission of data to and/or from the consumer. Said data line consists of two wires which are guided in a parallel manner relative to each other. Each of the data line wires is arranged adjacent to one of the two power line wires and in a manner that is symmetrical to a plane. The cross section of the conductor of the adjacent wire of the energy line is also symmetrical relative to the plane.

Abstract: A controllable transformer device comprising a body of a magnetic material, a primary winding wound round the body about a first axis, a secondary winding wound round the body about a second axis at right angles to the first axis, and a control winding wound the body about a third axis, coincident with the second axis. The device can be employed to provide a frequency controlled power supply.

Abstract: A high frequency transformer may include an integrated rectifier cell with flat windings and/or slotted copper segments stacked on a core branch to provide alternating primary and secondary windings. This reduces inductance leakage and thus increases the operating frequency of the transformer. Rectifying diodes of the rectifier cell may be arranged according to various configurations between the copper segments, and the collection plates may form one of the rectifier outputs. The other output may be provided by connecting all the midpoints of the windings with conductive spacers pressed together along a first axis. The invention is particularly advantageous in static converters, and, more particularly, in spot welding machines, for example.

Abstract: A coupling adjusting structure for a double-tuned circuit contains first and second coils that are configured such that a pair of first conductive patterns formed on a first surface of a printed circuit and a corresponding pair of second conductive patterns formed on a second surface of the printed circuit board are connected via corresponding connecting conductors. One end of the first coil and the corresponding end of the second coil are disposed close to each other. A first ground conductive pattern is disposed at least on the first surface of the printed circuit. A first jumper connected to the first ground conductive pattern is disposed between the first and second coils to adjust an inductive coupling of the double-tuned circuit.

Abstract: In a step-up transformer for magnetron driving in which two ferrite cores are opposed to each other with a gap G interposed therebetween, thereby forming a magnetic circuit including a middle core section, an outer core section and a coupling core section for coupling the middle core section and the outer core section, and a primary winding and a secondary winding are arranged to surround the middle core respectively, a sectional area of the middle core is increased, a number of winds in a radial direction of each of the primary winding and the secondary winding is increased and a number of winds in an axial direction is decreased, and the primary winding and the secondary winding are provided close to each other and a ratio of the sectional area of the middle core to that of the outer core is decreased to be 2:1 or less.

Abstract: An improved electromagnetic work coil for use with an electromagnetic force machine that produces a pulling (tension) force on a conductive panel work piece. The electromagnetic work coil comprises a coil with insulated conductor windings passing through a clamped stressing region. The work coil further contains mating terminals and is encapsulated in a nonmagnetic housing. A clamp on the stressing region comprises two clamp surfaces and a part in tension outside of the stressing region to tangentially compress the windings in the stressing region. The preferred embodiment the winding paths around the stressing region are made symmetric to provide a centered linear pulling area with a symmetric magnetic field. The conductor windings are tapered that increase in height and width outside of the stressing region to improve thermal and electrical conductivity and decrease the magnetic field outside of the stressing region.

Abstract: A superconducting transformer includes two pairs of axially extending windings (1, 2, 3 and 4). The windings are each in the from of a right cylindrical solenoid having a circular cross-section which are substantially concentrically nested. Each winding (1, 2, 3 and 4) includes a plurality of turns formed from superconducting tape. Each winding respectively includes a first end and a second end (5 and 6, 7 and 8, 9 and 10, and 11 and 12) which are configured for electrical connection with at least one of the other ends, and alternating power source (13), a load (14), or other passive or active electrical components. The ampere turns of a first pair of the windings (1 and 3), is substantially the same as the ampere turns of a second pair of the windings (2 and 4).

Abstract: A magnetic clamping arrangement (10) for holding the arrangement, and in particular a body (5), operably clamped with respect to a ferromagnetic surface (6) by way of a body datum face (8), comprises housing means (12) mounted on the body, and electromagnet (16) carried by the housing means. The electromagnet comprises a core (18), having three limbs 20.1, 20.2 and 20.3, each terminating in a pole face 22.1, 22.2 and 22.3, being formed by a plurality of ferromagnetic transformer laminations (26). stacked together and slideable with respect to each other in a direction to and from the pole faces. Lamination bias means (36), in the form of masses 38, 40.1 and 40.2 of resilient compressible material, delined quiescent pole faces from which individual laminations may depart by sliding when forced against a surface having ridges and/or grooves extending in the lamination planes, but exerts a restoring force on such laminations so displaced.

Abstract: An inductive device (10) comprises a magnetic core (16) including a portion of a plurality of wires (18), an electric winding (20) extending around said magnetic core, with one or more of the plurality of wires (18) at least partially encircling the electric winding (20) and having first and second end portions (26) arranged so as to form a gap (24) therebetween, and a flux coupling structure (28) disposed in a vicinity of the gap (24) so as to enhance coupling of magnetic flux between the first and second end portions (26).

Abstract: A transformer includes a ferrite base plate having ferrite core between two grooves, two or more windings wound around the ferrite core and engaged in the grooves of the ferrite base plate and electrically coupled together and separated from each other, for forming two spaces in the grooves of the ferrite base plate and formed between the windings. One or more conductive panels may be engaged into each of the spaces of the ferrite base plate for reducing the voltage generated by the windings, and for supplying a stabilized electric power source to electric devices.

Abstract: Monolithic inductance-enhancing integrated circuits, complementary metal oxide semiconductor (CMOS) inductance-enhancing integrated circuits, inductor assemblies, and inductance-multiplying methods are described. In one embodiment, a monolithic inductance-enhancing integrated circuit comprises a transistor supported by a bulk monocrystalline silicon substrate. An inductor assembly is supported by the substrate and operably connected with the transistor in an inductance-enhancing circuit configuration having a quality factor (Q) greater than 10. In another embodiment, a complementary metal oxide semiconductor (CMOS), inductance-enhancing integrated circuit includes a field effect transistor supported over a silicon-containing substrate and having a gate, a source, and a drain. A first inductor is received within an insulative material layer over the substrate, and is connected to the gate. A second inductor is received within the insulative material layer and is connected to the source.

Abstract: A winding device includes a core, a wire winding provided in the core, and a heat conductive material. The heat conductive material is provided around an outer surface of the wire winding to contact the wire winding and the core via the heat conductive material.

Abstract: A power transforming apparatus comprises at least two transformers connected parallel to each other between a common power source and a common output, each of said transformers including a primary and a secondary for transforming power from said same power source to said same output. The resistive loss is substantially decreased because the current is split among multiple transformers, and therefore the temperature of the transformer is kept low as less heat is produced from the transformer loss.

Abstract: A transformer core that can realize a winding having a fractional number of turns. At least one of the two side posts of the transformer core has a trench or a through hole. The winding on the side post passes through the trench or the through hole. For a POT-type transformer core, the trench or the through hole is formed on the bobbin, and winding passes through the trench or the through hole on the bobbin.

Abstract: The invention relates to a magnetic component having at least two windings electrically connected in series (3, 4, 13, 14, 24-27, 31-33) and a core (1, 2, 10, 11, 20-23, 30) on which the windings (3, 4, 13, 14, 24-27, 31-33) are arranged so that in the event of a current flow through the windings (3, 4, 13, 14, 24-27, 31-33) the generated magnetic stray fields outside the component at least partly compensate each other, the core having at least one inside limb portion and at least two outside limb portions and in that the windings (3, 4, 13, 14, 24-27, 31-33) are arranged on the inside limb portion and/or the outside limb portions.

Abstract: A core for a three-phase transformer, the core comprising a centrally-disposed flux collector and three generally C-shaped core leg sections peripherally arranged about the flux collector in an angularly spaced relationship and connected to the flux collector. The three core leg sections are each adapted to support a transformer coil and the flux collector is adapted to provide a low reluctance path to magnetically link the coils of the transformer.

Abstract: The invention relates to a high-voltage transformer consisting of conventional elements disposed in two different groups, namely positive voltage elements (1-5) and negative voltage elements (1′-5′), both types of elements being separated by a single insulating barrier (6). One of the ends of all elements has a ground level or “zero voltage” increasing progressively towards the other end in the positive voltage elements and decreasing progressively in the negative voltage elements in such a way that the elements in each group have equipotential voltages at the same level or distance from the ground level. Said structure eliminates parasitic capacitances and makes it possible to mount the elements very close to each other thereby considerably reducing size and consequently costs.

Abstract: An energy transfer element having an energy transfer element input winding and an energy transfer element output winding. In one aspect, the energy transfer element input winding is capacitively coupled to the energy transfer element output winding. The energy transfer element is capacitively coupled to electrical earth. One or more additional windings are introduced as part of the energy transfer element. The one or more additional windings substantially reduce capacitive displacement current between the energy transfer element input winding and energy transfer element output winding by balancing the relative electrostatic fields generated between these windings and/or between the energy transfer element and electrical earth by canceling the electrostatic fields generated by all windings within the energy transfer element relative to electrical earth through the selection of the physical position and number of turns in the additional windings.