# US 2013/0154777 A1 · Electromagnet for low field nmr measurements and method for manufacturing thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0154777 A1 - Document ID: US20130154777A1 - Status: Published application - Kind: A1 - Application number: 13/819,961 - Filed: 2011-09-22 - Published: 2013-06-20 - Earliest claimed: 2010-09-23 - Assignees: Metso Automation Oy - Inventors: Sami Virtanen; Jani Pakarinen - Web page: https://patentgrep.com/patent/US20130154777A1 ## CPC - H01F 7/06: Electromagnets; Actuators including electromagnets {(electric coils H01F5/00; devices for holding workpieces using electric force B23Q3/15; load-engaging elements for lifting articles electromagnetically B66C1/06; electromagnetic couplings F16D27/00; magnetic brakes F16D63/002; electromagnetically operated valves F16K11/24, F16K31/00; analysing materials by magnetic means G01N27/72, G01N27/80; electromagnets for winding mechanical clocks G04C1/02; electromagnetic relays H01H51/00; windings for salient poles of dynamo-electric machines H02K3/18; electromagnets for telegraphic communication H04L; for arc lamps H05B31/28)} - G01R 33/3802: {Manufacture or installation of magnet assemblies; Additional hardware for transportation or installation of the magnet assembly or for providing mechanical support to components of the magnet assembly} - G01R 33/381: using electromagnets - H01F 7/20: without armatures (cores H01F3/00; coils H01F5/00 {; shaping metal by applying magnetic forces B21D26/14; electromagnets specially adapted for NMR applications G01R33/381}) - H01F 41/064: Winding non-flat conductive wires, e.g. rods, cables or cords - G01N 24/082: {Measurement of solid, liquid or gas content} - H01F 27/346: {Preventing or reducing leakage fields (using magnetic shields H01F27/36; using auxiliary windings H01F27/38)} - 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) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract The invention relates to an electromagnet and a method manufacturing the same. The electromagnet includes a frame having a volume within, and a conductive wiring wound around the frame. In accordance with the invention the magnet includes at least two circular grooves having two walls parallel to the each other and perpendicular to the longitudinal axis of the frame, at least two wire stacks each including at least one substack, wherein the wire has a cross section, at least one of the walls separating the two circular grooves, and jump wiring interconnecting the stacks so that contributions from jump wires of the adjacent stacks to total axial directional current are cancelled in average by the current of the return current wire, such that their contribution to the resulting magnetic field at the sample volume is minimized. ## Claims ### Claim 1 Electromagnet comprising a frame having a volume within, and a conductive wiring wound around the frame comprising: the volume being a sample space, at least two circular grooves having two walls parallel to the each other and perpendicular to the longitudinal axis of the frame, at least two wire stacks in the grooves, each of the at least two wire stacks comprising at least one substack wound with a wire, wherein the wire has a cross section, at least one of the walls separating the two circular grooves, and jump wiring interconnecting the wire stacks so that contributions from jump wires of the adjacent stacks to total axial directional current are cancelled in average by the current of the return current wire, such that their contribution to the resulting magnetic field at the sample volume is minimized. ### Claim 2 (depends on 1) Electromagnet in accordance with claim 1, wherein, at least two wire stacks each comprise even number of substacks and at least two substacks and the substacks are wound in opposite directions. ### Claim 3 (depends on 1) Electromagnet in accordance with claim 1, wherein the at least two circular grooves have a rectangular cross section. ### Claim 4 (depends on 1) Electromagnet in accordance with claim 1, wherein at least the thickness of the wire is equalized. ### Claim 5 (depends on 1) Electromagnet in accordance with claim 1, comprising directing effective radial currents in adjacent stacks or stack pairs opposite to each other, such that their contribution to the resulting magnetic field at the sample volume is minimized. ### Claim 6 (depends on 1) Electromagnet according to claim 1, wherein the adjacent stacks or stack pairs are advantageously wound in alternating directions. ### Claim 7 (depends on 1) Electromagnet in accordance with claim 1, comprising arranging the interconnections of the stacks in such a way that contributions from jump wires of the adjacent stacks to total axial directional current are cancelled by the current of the return current wire, such that their contribution to the resulting magnetic field at the sample volume is minimized. ### Claim 8 (depends on 1) Electromagnet in accordance with claim 1, wherein the wire stacks are arranged in planes orthogonal to the frame symmetry axis. ### Claim 9 A method for manufacturing an electromagnet, comprising: forming a frame having a volume as a sample space within, and providing the frame with a conductive wiring comprising: forming at least two circular grooves having two walls parallel to the each other and perpendicular to the longitudinal axis of the frame, winding at least two wire stacks in the grooves, each comprising at least one substack, wound with a wire, wherein the wire has a cross section, at least one of the walls separates the two circular grooves, and connecting adjacent wire stacks together with jump wiring so that effective radial currents in adjacent stacks are directed opposite to each other, such that their contribution to the resulting magnetic field at the sample volume is minimized. ### Claim 10 (depends on 9) Method according to claim 9, wherein there are an even number of substacks, at least two substacks, wherein the wire has a cross section and the substacks are wound in opposite directions. ### Claim 11 (depends on 10) A method according to claim 10, comprising: forming at least two circular grooves having a rectangular cross section on the outer surface of the frame, winding at least two wire stacks each comprising two substacks, wherein the wire has rectangular cross section and the substacks are wound in opposite directions, on the grooves of the frame. ### Claim 12 (depends on 10) A method in accordance with claim 10, including equalizing at least the thickness of the wire. ### Claim 13 (depends on 9) A method in accordance with claim 9, comprising arranging the interconnections of the stacks in such a way that contributions from adjacent stacks to total axial directional current are cancelled in average by the current of the return current wire, such that their contribution to the resulting magnetic field at the sample volume is minimized. ### Claim 14 (depends on 11) A method in accordance with claim 11, including equalizing at least the thickness of the wire by rolling. ### Claim 15 (depends on 14) A method in accordance with claim 14, including equalizing at least the thickness of the wire by rolling after the applying of the insulator coating on the conductor wire.