# US 2017/0287629 A1 · Resonant Transformer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0287629 A1 - Document ID: US20170287629A1 - Status: Published application - Kind: A1 - Application number: 15/620,541 - Filed: 2017-06-12 - Published: 2017-10-05 - Earliest claimed: 2014-10-03 - Assignees: Instrument Manufacturing Company - Applicants: Instrument Manufacturing Company - Inventors: Matthew S. Mashikian; Andrzej Pawel Szatkowski - Web page: https://patentgrep.com/patent/US20170287629A1 ## CPC - H01F 29/00: Variable transformers or inductances not covered by group H01F21/00 {(tap change devices H01H9/0005)} - H01F 27/24: Magnetic cores - H01F 27/28: Coils; Windings; Conductive connections - H01F 27/289: {with auxiliary windings (for pancake coils H01F27/2871)} - H01F 27/38: Auxiliary core members; Auxiliary coils or windings - H01F 29/10: having movable part of magnetic circuit {(high leakage transformers H01F38/08; dynamo-electric machines with movable part of magnetic circuit H02K23/44, H02K23/48)} - G01R 31/1254: {of gas-insulated power appliances or vacuum gaps (testing switches G01R31/327; detecting electrical or mechanical defects in encased switchgear H02B13/065)} - G01R 31/62: Testing of transformers - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract Exemplary embodiments of the present disclosure are directed to resonant transformers (or reactors) and coil arrangements associated with resonant transformers. The coil arrangements can include a grounding coil configured to generate a net-zero induced voltage between a first end of the grounding coil and a second end of the grounding coil layer, and one or more step-up coil layers formed by one or more layers of pressure tape, insulating materials, and wire wrapped to form coils about a portions of a split magnetic core. The split magnetic core can include a first core segment and a second core segment, where one of the core segments is disposed within a main housing and one of the core segments is disposed external to the main housing. A gap between the first and second core segments can be manipulated to control an inductance of the resonant transformer. ## Claims ### Claim 1 A resonant transformer comprising: a magnetic core; a core mandrel wrapped over a leg of the magnetic core; and a coil having a coil arrangement wrapped coaxially and concentrically over the core mandrel, the coil arrangement includes: a grounding coil layer configured to provide a net-zero induced voltage between opposite ends of the ground coil layer; and a plurality of step coil layers, the plurality of step coil layers being wound coaxially and concentrically about the grounding coil layer, wherein each successive step-up coil layer in the plurality of step-up coil layers includes fewer turns than a preceding step-up coil lay in the plurality of step-up coil layers. ### Claim 2 (depends on 1) The resonant transformer of claim 1, wherein each end of the coil arrangement includes grading tape to control an electrical stress along each end of the coil arrangement. ### Claim 3 (depends on 1) The resonant transformer of claim 1, wherein the grounding coil layer includes a grounding coil alternating between a specified number of turns in a first direction and the specified number of turns in a second direction. ### Claim 4 (depends on 3) The resonant transformer of claim 3, wherein a total number of turns in the first direction equals a total number of turns in the second direction between a first end and a second end of the grounding coil. ### Claim 5 (depends on 1) The resonant transformer of claim 1, wherein the grounding coil layer comprises a grounding coil sandwiched between two layers of pressure tape. ### Claim 6 (depends on 1) The resonant transformer of claim 1, wherein at least one of the step-up coil layers comprises: a step-up coil; a layer of pressure tape covering the step-up coil; an layer of insulating material covering the layer of pressure tape; and a further layer of pressure tape covering the layer of insulating material. ### Claim 7 (depends on 1) The resonant transformer of claim 1, further comprising: a housing, at least the leg of the magnetic core, the core mandrel, and the coil are disposed within the housing. ### Claim 8 (depends on 7) The resonant transformer of claim 7, wherein the housing is filled with air or an inert gas. ### Claim 9 (depends on 7) The resonant transformer of claim 7, wherein the magnetic core includes a first core segment that includes the leg and a second core segment that is spaced away from the first core segment to define a gap that is devoid of a magnetic material. ### Claim 10 (depends on 9) The resonant transformer of claim 9, wherein a size of the gap is adjustable to change an inductance of the resonant transformer. ### Claim 11 (depends on 7) The resonant transformer of claim 7 wherein a gap is formed in the magnetic core and a size of the gap is adjustable to change an inductance of the resonant transformer. ### Claim 12 A coil arrangement for a transformer comprising: a grounding coil wound concentrically about and spaced away from a magnetic core of a transformer, the grounding coil being wound in alternating directions along a portion of the magnetic core to generate an induced voltage between a first end of the ground coil and a second end of the grounding coil that is substantially zero. ### Claim 13 (depends on 12) The coil arrangement of claim 12, wherein the grounding coil is wound a first number of turns in first circumferential direction about the magnetic core and wound a second number of turns in a second circumferential direction about the magnetic core. ### Claim 14 (depends on 13) The coil arrangement of claim 13, wherein the first number of turns is disposed adjacent to the second number of turns. ### Claim 15 (depends on 13) The coil arrangement of claim 13, wherein the first number of turns equals the second number of turns. ### Claim 16 (depends on 12) The coil arrangement of claim 12, further comprising: a first layer of insulating material disposed concentrically about a portion of a magnetic core of a transformer and sandwiched between layers of pressure tape, the grounding coil wound concentrically about and spaced away from a magnetic core of a transformer by at least the first layer of insulating material and the layers of pressure tape; a second layer of insulating material disposed concentrically over the grounding coil and sandwiched between further layers of pressure tape. ### Claim 17 A coil arrangement for a transformer comprising: a step-up coil layer that includes: a course of wire wound concentrically about and spaced away from a magnetic core of a transformer; a layer of pressure tape disposed concentrically over the course of wire; a layer of insulating material disposed circumferential over the layer of pressure tape; and a further layer of pressure tape disposed concentrically over the layer of insulating material. ### Claim 18 (depends on 17) The coil arrangement of claim 17, further comprising: a further step coil layer disposed circumferential and coaxially over the step-up coil layer, the further step-up coil layer, the further step-up coil layer including: a further course of wire wound concentrically about the further layer of pressure tape, the further course of wire compressing the layer of insulating material in the step-up coil layer; a still further layer of pressure tape disposed concentrically over the further course of wire; a further layer of insulating material disposed circumferential over the further layer of pressure tape; and a still further layer of pressure tape disposed concentrically over the layer of insulating material. ### Claim 19 (depends on 17) The coil arrangement of claim 17, wherein the further course of wire is wound by fewer turns than the course of wire.