# US 7,746,203 B2 · Thermodynamic cycles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,746,203 B2 - Document ID: US7746203B2 - Status: Granted - Kind: B2 - Application number: 11/809,330 - Filed: 2007-05-30 - Published: 2008-12-04 - Granted: 2010-06-29 - Earliest claimed: 2007-05-30 - Inventors: Remi Oseri Cornwall - Web page: https://patentgrep.com/patent/US7746203B2 ## CPC - H10N 15/20: Thermomagnetic devices using thermal change of the magnetic permeability, e.g. working above and below the Curie point - H02K 44/085: {with conducting liquids} - F25B 21/00: Machines, plants or systems, using electric or magnetic effects - Y02B 30/00: Energy efficient heating, ventilation or air conditioning [HVAC] - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract One embodiment disclosed herein is an apparatus for performing a thermodynamic cycle comprising: a sample that exhibits temporary magnetic remanence; and a magnetisation apparatus for magnetising the sample, wherein the magnetisation apparatus is operable, during a first part of the thermodynamic cycle, to produce a cyclically-varying magnetising field comprising a wavetrain of a single or plurality of consecutive cycles, and to remove the magnetising field from the sample during a second part of the thermodynamic cycle, wherein demagnetisation of the sample during the second part of the thermodynamic cycle causes the generation of an independent magnetic flux. ## Claims ### Claim 1 An apparatus for performing a thermodynamic cycle, comprising: a sample that exhibits temporary magnetic remanence; and a magnetisation apparatus for magnetising the sample, wherein the magnetisation apparatus is operable, during a first part of the thermodynamic cycle, to produce a cyclically-varying magnetising field comprising a wavetrain of a plurality of consecutive cycles, and to remove the magnetising field from the sample during a second part of the thermodynamic cycle, wherein demagnetisation of the sample during the second part of the thermodynamic cycle causes the generation of an independent magnetic flux. ### Claim 2 (depends on 1) An apparatus according to claim 1, wherein the cyclically-varying magnetising field is a substantially sinusoidally-varying magnetising field. ### Claim 3 (depends on 2) An apparatus according to claim 2, wherein the magnetising field produces a substantially sinusoidally-varying magnetic flux in the sample. ### Claim 4 (depends on 1) An apparatus according to claim 1, wherein the sample is a ferrofluid or ferroset with heat conduction channels therethrough. ### Claim 5 (depends on 1) An apparatus according to claim 1 wherein the wavetrain comprises at least five consecutive cycles of the magnetising field. ### Claim 6 (depends on 1) An apparatus according to claim 1 wherein the wavetrain comprises at least ten consecutive cycles of the magnetising field. ### Claim 7 (depends on 1) An apparatus according to claim 1, wherein the magnetisation apparatus also comprises a power collection apparatus, in which power is generated during the second part of the thermodynamic cycle by the independent magnetic flux. ### Claim 8 A method of convening energy, comprising the steps of: providing a sample that exhibits temporary magnetic remanence; magnetising the sample, during a first part of a thermodynamic cycle, by producing a cyclically-varying magnetising field comprising a wavetrain of a plurality of consecutive cycles; and removing the magnetising field from the sample during a second part of the thermodynamic cycle, thereby allowing the sample to demagnetise, the demagnetisation of the sample causing the generation of an independent magnetic flux. ### Claim 9 (depends on 8) A method according to claim 8, further comprising the step of convening at least some of the independent magnetic flux into an electric current. ### Claim 10 An apparatus for performing a thermodynamic cycle, comprising: a sample that exhibits temporary magnetic remanence; and a magnetisation apparatus for magnetising the sample, wherein the magnetisation apparatus is operable, during a first part of the thermodynamic cycle, to produce a substantially sinusoidally-varying magnetising field, thus producing a substantially sinusoidal variation of magnetic flux in the sample, and to remove the magnetising field from the sample during a second part of the thermodynamic cycle, wherein demagnetisation of the sample during the second part of the thermodynamic cycle causes the generation of an independent magnetic flux. ### Claim 11 (depends on 10) An apparatus according to claim 10, wherein the sample is a ferrofluid or a ferroset with heat conduction channels therethrough. ### Claim 12 A method of converting energy, comprising the steps of: providing a sample that exhibits temporary magnetic remanence; magnetising the sample, during a first part of a thermodynamic cycle, by producing a substantially sinusoidally-varying magnetising field, thus producing a substantially sinusoidal variation of magnetic flux in the sample; and removing the magnetising field from the sample during a second part of the thermodynamic cycle, thereby allowing the sample to demagnetise, the demagnetisation of the sample causing the generation of an independent magnetic flux. ### Claim 13 (depends on 12) A method according to claim 12, further comprising the step of converting at least some of the independent magnetic flux into an electric current.