# US 9,355,770 B2 · Transformer with improved power handling capacity > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,355,770 B2 - Document ID: US9355770B2 - Status: Granted - Kind: B2 - Application number: 14/522,195 - Filed: 2014-10-23 - Published: 2015-10-22 - Granted: 2016-05-31 - Earliest claimed: 2014-04-22 - Assignees: Transformers, LLC - Applicants: Transformers, LLC - Inventors: Jack Aaron; Herbert Shapiro; Robert Johnson - Web page: https://patentgrep.com/patent/US9355770B2 ## CPC - H01F 41/064: Winding non-flat conductive wires, e.g. rods, cables or cords - G06F 30/36: Circuit design at the analogue level - G06F 30/373: Design optimisation - G06F 30/39: Circuit design at the physical level (physical level design for reconfigurable circuits G06F30/347) - G06F 30/398: Design verification or optimisation, e.g. using design rule check [DRC], layout versus schematics [LVS] or finite element methods [FEM] (optical proximity correction [OPC] design processes G03F1/36) - H01F 3/10: Composite arrangements of magnetic circuits - H01F 27/24: Magnetic cores - H01F 27/245: made from sheets, e.g. grain-oriented (H01F27/26 takes precedence) - H01F 27/28: Coils; Windings; Conductive connections - H01F 27/2823: {Wires (H01F27/2866 takes precedence)} - H01F 27/325: {Coil bobbins (formers for coils in general H01F5/02)} - H01F 41/079: Measuring electrical characteristics while winding - G06F 2111/04: Constraint-based CAD - G06F 2111/06: Multi-objective optimisation, e.g. Pareto optimisation using simulated annealing [SA], ant colony algorithms or genetic algorithms [GA] - G06F 2111/20: Configuration CAD, e.g. designing by assembling or positioning modules selected from libraries of predesigned modules - G06F 2119/06: Power analysis or power optimisation - Y02E 40/70: Smart grids as climate change mitigation technology in the energy generation sector - Y04S 10/50: Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications - Y10T 29/49071: by winding or coiling - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y04S: SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Disclosed is an electrical transformer for improved transformer power capacity and efficiency designed by the application of disclosed design considerations. One embodiment design consideration is a method to configure power transformer windings wherein the minimum distance of the primary windings from the winding axis/core center is greater (the primary windings are more distal) from the winding axis than the minimum distance of the secondary windings, which are wound around the minimum interior core diameter. This design consideration is extended from single bobbin transformer designs to split bobbin designs, with the requisite distal increase of the primary windings (from the core axis) geometrically provided by an enlarged core bobbin center leg (axial) dimension beneath the primary winding window. Another disclosed design consideration is to fix the primary winding length relationship to the core weight for given transformer specifications in accordance with the disclosed unexpected experimental results and formula. ## Claims ### Claim 1 A method for designing a transformer comprising: setting specifications for the transformer input voltage, output voltage, and power capacity, setting the primary winding length as a fixed length according to an empirically derived optimization formula, estimating an initial secondary winding length by calculating the secondary length L to be the specified secondary voltage multiplied by said primary winding length divided by the specified primary voltage, determining minimum wire gauges for the primary and secondary windings necessary to meet said specified power capacity wherein the initial winding lengths and determined initial wire gauges form the initial primary and the initial secondary windings, winding the initial secondary winding around a selected secondary core segment, winding the initial primary winding around a selected primary core segment, testing the output voltage of the transformer to determine whether the output voltage meets the output voltage specification, modifying iteratively the secondary winding length and rewinding and retesting the output voltage until the output voltage meets the output voltage specification, testing the width of wound secondary winding to determine whether the secondary windings fill the selected secondary core segment, modifying iteratively the secondary winding gauge and rewinding and retesting the secondary windings until the secondary windings fill the selected secondary core segment, testing the width of wound primary winding to determine whether the primary windings fill the selected primary core segment, modifying iteratively the primary winding gauge and rewinding and retesting the primary windings until the primary windings fill the selected primary core segment. ### Claim 2 (depends on 1) A method as in claim 1 wherein the selected primary core segment and the selected secondary core segment are the center leg of a stack of E shaped core laminations. ### Claim 3 (depends on 1) A method as in claim 1 wherein the selected primary core segment and the selected secondary core segment are the center leg of a stack of E shaped core laminations, wherein said primary windings are wound on top of said secondary windings. ### Claim 4 (depends on 1) A method as in claim 1 wherein the selected primary core segment is a center leg of a first stack of E shaped core laminations and the selected secondary core segment is a center leg of a second stack of E shaped core laminations which mirrors the orientation of the first stack of core laminations. ### Claim 5 (depends on 1) A method as in claim 1 wherein the selected primary core segment is a center leg of a first stack of E shaped core laminations and the selected secondary core segment is a center leg of a second stack of E shaped core laminations which mirrors the orientation of the first stack of core laminations, and wherein the center leg of the first stack of core laminations is wider than the center leg of the second stack of core laminations. ### Claim 6 (depends on 1) A method as in claim 1 wherein the selected primary core segment is a first portion of a center leg of a stack of E shaped core laminations and the selected secondary core segment is a second portion of the stack of E shaped core laminations wherein the first portion of the center leg is wider than the second portion of the center leg. ### Claim 7 (depends on 1) A method as in claim 1 wherein the selected primary core segment and the selected secondary core segment are the circumference of a toroidal magnetic core, wherein said primary windings are wound on top of said secondary windings. ### Claim 8 (depends on 1) A method as in claim 1 wherein the transformer is a step-down transformer. ### Claim 9 A method for designing a transformer comprising: setting initial primary and secondary voltages and power capacity for the transformer wherein the transformer is a step-down transformer, setting the weight and magnetic permeability of the transformer core, setting the conductive material used for primary and secondary windings for the transformer, determining the length of a primary winding according to an empirical and empirically derived relationship between the core weight and the fixed primary winding length according to the set primary and secondary voltages, power capacity, primary and secondary winding material, and core magnetic permeability, configuring the transformer to meet the specified primary and secondary voltages and the power capacity based upon the determined primary winding length. ### Claim 10 (depends on 9) A method as in claim 9 wherein the input voltage is set to be 120V, the core magnetic permeability is M19, and the primary and secondary windings are copper, determining the primary winding length/in feet according to the core weight c in pounds by the relationship l=−52.5*ln(c)+280. ### Claim 11 A method for designing a transformer comprising: setting initial primary and secondary voltages and power capacity for the transformer wherein the transformer is a step-down transformer, setting the weight and magnetic permeability of the transformer core, setting the conductive material used for primary and secondary windings for the transformer, calculating the primary winding length by a means forweight and the fixed primary winding length according to the set primary and secondary voltages, power capacity, primary and secondary winding material, and core magnetic characteristics, configuring the transformer to meet the specified primary and secondary voltages and the power capacity based upon the determined primary winding length. ### Claim 12 A method for manufacturing a transformer comprising: configuring a magnetic core of a specified magnetic material defining a geometry with a space for a primary and a secondary winding, determining a length of said primary winding by a formula which includes as inputs a core weight, a specified primary voltage, a specified output voltage, the specified magnetic material, and a specified input idle current, determining a length and gauge of said secondary winding according to a ratio of said specified primary voltage and said specified secondary voltage multiplied by a number of turns determined by the length of said primary winding length and optimized to utilize said space, winding said secondary winding about a bobbin which engages said core, winding said primary winding about said bobbin outside of said secondary winding, affixing said bobbin to a selected segment of said core. ### Claim 13 (depends on 12) A method for manufacturing a transformer as in claim 12, wherein said winding of said secondary winding and the winding of said primary winding is about a split bobbin which laterally spaces the primary and secondary windings, wherein said primary winding minimal axial distance from an axial center of said selected core segment is greater than said secondary winding minimal axial distance from said axial center of said selected core segment.