EP0209215A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Ferromagnetic element with temperature regulation
Assignee: Metcal Inc
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Filing: 1986-04-29
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Granted: —
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Expires: 2006-04-29
Abstract
Abstract A ferromagnetic element has current passed through it either by direct electrical connections or by induction. The current through the ferromagnetic element may be far greater than is necessary to heat the element above its effective Curie temperature. As the element is heated and is passing through its effective Curie transition (that is its temperature is rising from below its effective Curie temperature to, or above, its effective Curie temperature) the change in permeability of the element is sensed and the current through the element is cut off. The element then cools. When the temperature falls below the effective Curie temperature, the full current is restored. The heating and cooling process repeats itself indefinitely. The result is that the element is maintained at its effective Curie by a pulsating current fed to the element. The Curie transition may be sensed by directly sensing changes in permeability as by an auto-transformer winding, on the element; or by sensing changes in the power to the element by reason of the change in resistance of the element as it passes through the effective Curie temperature.
Inventors
- 👤 D. Hall William
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 08:17
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/26; H; H05; H05B; H05B3/00; H05B3/0019; H05B3/0023; H05B6/00; H05B6/02; H05B6/06; H05B2213/00; H05B2213/07
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
141 words
The method of temperature regulation comprising: providing an element composed of material having a parameter which changes in a predetermined way in response to an increase in temperature to a given temperature, passing an electric current, of sufficient amplitude which if fed through said element for a prolonged period will heat said element well above said given temperature, sensing said change in said predetermined way and reducing or turning off the flow of said current through said element in response to said change, restoring said amplitude of said current to said element after a selected predetermined time, said sensing and restoring steps recurring alternately at such a rate as to provide a pulsating current that holds said element at about said given temperature and at all times prevents a rise in the temperature of said element substantially above said given temperature.
Claim 2
Independent Claim
141 words
The method of temperature regulation comprising: providing an element composed of material having a parameter which changes in a predetermined way in response to an increase in temperature to a given temperature, passing an electric current, of sufficient amplitude which if fed through said element for a prolonged period will heat said element well above said given temperature, sensing said change in said predetermined way and reducing or turning off the flow of said current through said element in response to said change, restoring said amplitude of said current to said element after a selected predetermined time, said sensing and restoring steps recurring alternately at such a rate as to provide a pulsating current that holds said element at about said given temperature and at all times prevents a rise in the temperature of said element substantially above said given temperature.
Claim 3
Dependent Claim
130 words
Temperature regulating apparatus, comprising: an electrical conducting element having a parameter that changes in a predetermined way as the temperature of the element rises to a given temperature, power delivery means feeding an electric current through said element of sufficient amplitude that if maintained indefinitely would heat said element far above said given temperature, and means for repeatedly (a) sensing a change in said predetermined way and reducing or turning off said electric current to said element in response to the sensing of a change in said predetermined way during an increase in temperature of said element, and (b) subsequently restoring after a predetermined time interval said amplitude of said electric current to said element, to thereby produce a pulsating current that holds said element at about said given temperature.
Claim 4
Dependent Claim
130 words
Temperature regulating apparatus, comprising: an electrical conducting element having a parameter that changes in a predetermined way as the temperature of the element rises to a given temperature, power delivery means feeding an electric current through said element of sufficient amplitude that if maintained indefinitely would heat said element far above said given temperature, and means for repeatedly (a) sensing a change in said predetermined way and reducing or turning off said electric current to said element in response to the sensing of a change in said predetermined way during an increase in temperature of said element, and (b) subsequently restoring after a predetermined time interval said amplitude of said electric current to said element, to thereby produce a pulsating current that holds said element at about said given temperature.
Claim 5
Dependent Claim
128 words
Temperature regulating apparatus, comprising: a ferromagnetic element having a permeability substantial greater than one when its temperature is below its effective Curie temperature and a permeability on the order of one when its temperature is above its effective Curie temperature, power delivery means feeding an electric current through said element of sufficient amplitude that if maintained indefinitely would heat said element far above its effective Curie temperature, so that said element has a Curie transition, and means for sensing at least a part of said Curie transition and turning off said electric current to said element in response to the sensing of at least a part of said Curie transition during an increase in temperature of said element, and for subsequently restoring said electric current to said element.
Claim 6
Dependent Claim
128 words
Temperature regulating apparatus, comprising: a ferromagnetic element having a permeability substantial greater than one when its temperature is below its effective Curie temperature and a permeability on the order of one when its temperature is above its effective Curie temperature, power delivery means feeding an electric current through said element of sufficient amplitude that if maintained indefinitely would heat said element far above its effective Curie temperature, so that said element has a Curie transition, and means for sensing at least a part of said Curie transition and turning off said electric current to said element in response to the sensing of at least a part of said Curie transition during an increase in temperature of said element, and for subsequently restoring said electric current to said element.
Claim 7
Dependent Claim
131 words
Temperature regulating apparatus as defined in claim 3 in which said power delivery means is directly connected by an ohmic connection to said element to thereby pass said alternating current through said element said element having a current carrying portion, said current being a current varying at a rate relative to the size of said element so that the current is concentrated along at least one surface of said element below the effective Curie temperature and spreads deeper into the element as the effective Curie temperature is approached so that if one part of the current carrying portion of said element is cooled more than another part of said element the said one part will receive increased heat due to the decreased skin depth of the current in such one part.
Claim 8
Dependent Claim
122 words
Temperature regulating apparatus as defined in Claim 3 in which said power delivery means comprise means for inducing said alternating current in said element. said element having a current carrying portion, said current being a current varying at a rate relative to the size of said element so that the current is concentrated along at least one surface of said element below the effective Curie temperature and spreads deeper into the element as the effective Curie temperature is approached so that if one part of the current carrying portion of said element is cooled more than another part of said element the said one part will receive increased heat due to the decreased skin depth of the current in such one part.
Claim 9
Dependent Claim
48 words
Temperature regulating apparatus as defined in claim 3 in which said sensing means comprises inducing magnetization B to said element and detecting the magnetic field H produced thereby and turning off said alternating current to said element in response to a given decrease in said magnetic field H.
Claim 10
Dependent Claim
44 words
Temperature regulating apparatus as defined in claim 3 in which said sensing means comprises means for detecting a change in the power of said alternating current as the temperature of said element increases and said element undergoes at least part of a Curie transition.
Claim 11
Dependent Claim
28 words
Temperature regulating apparatus as defined in claim 7 in which said sensing means comprises means that responds to a change in voltage to detect said change in power.
Claim 12
Dependent Claim
28 words
Temperature regulating apparatus as defined in claim 7 in which said sensing means comprises means that responds to a change in current to detect said change in power.
Claim 13
Dependent Claim
43 words
Temperature regulating apparatus as defined in claim 3 in which said sensing means includes means for restoring said current to said element at the end of a predetermined time interval following the time that said current was turned off by said sensing means.
Claim 14
Dependent Claim
41 words
Temperature regulating apparatus as defined in claim 3 in which said sensing means comprises means for sensing an increase in permeability of said element and restoring said current to said element in response to an increase in permeability of said element.
Claim 15
Independent Claim
117 words
The method of temperature regulation comprising: providing an element composed of ferromagnetic material having a permeability considerably greater than one below its effective Curie temperature and a permeability on the order of one above its effective Curie temperature, passing an alternating current through said element of sufficient magnitude to heat said element substantially above its effective Curie temperature so that said element has a Curie transition, sensing at least a part of said Curie transition and stopping the flow of current in said element when at least a part of the Curie transition is sensed, and restoring the current to said element when the temperature of said element falls and the permeability of said element increases substantially.
Claim 16
Independent Claim
117 words
The method of temperature regulation comprising: providing an element composed of ferromagnetic material having a permeability considerably greater than one below its effective Curie temperature and a permeability on the order of one above its effective Curie temperature, passing an alternating current through said element of sufficient magnitude to heat said element substantially above its effective Curie temperature so that said element has a Curie transition, sensing at least a part of said Curie transition and stopping the flow of current in said element when at least a part of the Curie transition is sensed, and restoring the current to said element when the temperature of said element falls and the permeability of said element increases substantially.
Claim 17
Dependent Claim
41 words
The method of claim 12 in which said sensing step comprises applying magnetic induction to said element and sensing the resulting magnetic field in the element to thus determine when the element passes through at least part of the Curie transition.
Claim 18
Dependent Claim
29 words
The method of claim 12 in which an increase in the permeability of said element is sensed; and said current is restored when such increase in permeability is sensed.
Claim 19
Dependent Claim
127 words
Temperature regulating apparatus, comprising: a ferromagnetic element having a permeability substantially greater than one when its temperature is below its effective Curie temperature and a permeability on the order of one when its temperature is above its effective Curie temperature, power delivery means feeding an alternating current through said element of sufficient amplitude to heat said element above its effective Curie temperature, so that said element has at least part of a Curie transition, and means for sensing at least a part of said Curie transition and turning off said alternating current to said element in response to the sensing of at least a part of said Curie transition during an increase in temperature of said element, and for subsequently restoring said alternating current to said element.
Claim 20
Dependent Claim
127 words
Temperature regulating apparatus, comprising: a ferromagnetic element having a permeability substantially greater than one when its temperature is below its effective Curie temperature and a permeability on the order of one when its temperature is above its effective Curie temperature, power delivery means feeding an alternating current through said element of sufficient amplitude to heat said element above its effective Curie temperature, so that said element has at least part of a Curie transition, and means for sensing at least a part of said Curie transition and turning off said alternating current to said element in response to the sensing of at least a part of said Curie transition during an increase in temperature of said element, and for subsequently restoring said alternating current to said element.
Claim 21
Dependent Claim
33 words
Temperature regulating apparatus as defined in claim 15 in which said power delivery means is directly connected by an ohmic connection to said element to thereby pass said alternating current through said element.
Claim 22
Dependent Claim
24 words
Temperature regulating apparatus as defined in claim 15 in which said power delivery means comprises means for inducing said alternating current in said element.
Claim 23
Dependent Claim
48 words
Temperature regulating apparatus as defined in claim 15 in which said sensing means comprises inducing magnetization B to said element and detecting the magnetic field H produced thereby and turning off said alternating current to said element in response to a given decrease in said magnetic field H.
Claim 24
Independent Claim
103 words
The method of temperature regulation comprising: providing an element composed of ferromagnetic material having a permeability considerably greater than one below its effective Curie temperature and a permeability on the order of one above its effective Curie temperature, passing an alternating current through said element of sufficient magnitude to heat said element substantially above its effective Curie temperature so that said element has at least part of a Curie transition, and sensing at least a part of said Curie transition, by sensing a change in flux in said element and reducing the flow of current in said element when the flux is reduced.
Claim 25
Independent Claim
103 words
The method of temperature regulation comprising: providing an element composed of ferromagnetic material having a permeability considerably greater than one below its effective Curie temperature and a permeability on the order of one above its effective Curie temperature, passing an alternating current through said element of sufficient magnitude to heat said element substantially above its effective Curie temperature so that said element has at least part of a Curie transition, and sensing at least a part of said Curie transition, by sensing a change in flux in said element and reducing the flow of current in said element when the flux is reduced.
Claim 26
Dependent Claim
18 words
The method of claim 19 in which said current is stopped when a reduction in flux is sensed.
Claim 27
Dependent Claim
123 words
Temperature regulating apparatus, comprising: a ferromagnetic element having a permeability substantially greater than one when its temperature is below its effective Curie temperature and a permeability on the order of one when its temperature is above its effective Curie temperature, power delivery means feeding an alternating current through said element of sufficient amplitude to heat said element above its effective Curie temperature, so that said element has a Curie transition, and means for sensing at least a part of said Curie transition by sensing a decrease in the magnetic flux in said element, and reducing said alternating current to said element in response to the sensing of a decrease flux in said element, and for subsequently restoring said alternating current to said element.
Claim 28
Dependent Claim
123 words
Temperature regulating apparatus, comprising: a ferromagnetic element having a permeability substantially greater than one when its temperature is below its effective Curie temperature and a permeability on the order of one when its temperature is above its effective Curie temperature, power delivery means feeding an alternating current through said element of sufficient amplitude to heat said element above its effective Curie temperature, so that said element has a Curie transition, and means for sensing at least a part of said Curie transition by sensing a decrease in the magnetic flux in said element, and reducing said alternating current to said element in response to the sensing of a decrease flux in said element, and for subsequently restoring said alternating current to said element.
Claim 29
Dependent Claim
26 words
Temperature regulating apparatus as defined in claim 21 in which said last-named means cuts off current to said element in response to said decrease in flux.
Claim 30
Independent Claim
163 words
The method of temperature regulation comprising: providing an element composed of ferromagnetic material having a permeability considerably greater than one below its effective Curie temperature and a permeability on the order of one above its effective Curie temperature, passing an alternating current through said element of sufficient magnitude to heat said element substantially above its effective Curie temperature so that said element has a Curie transition thereby changing said power, sensing at least a part of said Curie transition by sensing a change in power to said element and reducing and the flow of current to said element when said power declines, and restoring the current to said element when the temperature of said element falls and the permeability of said element increases substantially, the frequency of said alternating current and the size of said element being so related that the electrical resistance of said element to said alternating current substantially decreases as the temperature of said element rises through the Curie transition.
Claim 31
Independent Claim
163 words
The method of temperature regulation comprising: providing an element composed of ferromagnetic material having a permeability considerably greater than one below its effective Curie temperature and a permeability on the order of one above its effective Curie temperature, passing an alternating current through said element of sufficient magnitude to heat said element substantially above its effective Curie temperature so that said element has a Curie transition thereby changing said power, sensing at least a part of said Curie transition by sensing a change in power to said element and reducing and the flow of current to said element when said power declines, and restoring the current to said element when the temperature of said element falls and the permeability of said element increases substantially, the frequency of said alternating current and the size of said element being so related that the electrical resistance of said element to said alternating current substantially decreases as the temperature of said element rises through the Curie transition.
Claim 32
Dependent Claim
18 words
The method of claim 23 in which said current is cut-off when a decline in power is sensed.
Claim 33
Dependent Claim
159 words
Temperature regulating apparatus, comprising: a ferromagnetic element having a permeability substantially greater than one when its temperature is below its effective Curie temperature and a permeability on the order of one when its temperature is above its effective Curie temperature, power delivery means feeding an alternating current through said element of sufficient amplitude to heat said element above its effective Curie temperature, so that said element has a Curie transition, and means for sensing at least a part of said Curie transition and for reducing said alternating current to said element in response to the sensing of a change in the power to said element, and for subsequently restoring said alternating current to said element, the frequency of said alternating current and the size of said element being so related that the electrical resistance to said alternating current substantially decreases and said power changes as the temperature of said element is increasing and is going through a Curie transition.
Claim 34
Dependent Claim
159 words
Temperature regulating apparatus, comprising: a ferromagnetic element having a permeability substantially greater than one when its temperature is below its effective Curie temperature and a permeability on the order of one when its temperature is above its effective Curie temperature, power delivery means feeding an alternating current through said element of sufficient amplitude to heat said element above its effective Curie temperature, so that said element has a Curie transition, and means for sensing at least a part of said Curie transition and for reducing said alternating current to said element in response to the sensing of a change in the power to said element, and for subsequently restoring said alternating current to said element, the frequency of said alternating current and the size of said element being so related that the electrical resistance to said alternating current substantially decreases and said power changes as the temperature of said element is increasing and is going through a Curie transition.
Claim 35
Dependent Claim
30 words
Temperature regulating apparatus as defined in claim 25 in which said last-named means comprises means for cutting off the current to said element when a decline in power is sensed.
Claim 36
Independent Claim
165 words
The method of temperature regulation comprising providing an element composed of ferromagnetic material having a permeability considerably greater than one below its effective Curie temperature and a permeability on the order of one above its effective Curie temperature, passing an electric current, of sufficient amplitude which if fed through said element for a prolonged period will heat said element well above its effective Curie temperature, to heat said element at least to a temperature high enough so that at least a part of the Curie transition takes place, sensing at least part of said Curie transition and reducing the flow of said current through said element when at least part of said Curie transition is sensed, and restoring said current to said element, said sensing and restoring steps recurring alternately to thus provide a pulsating current that holds said element at about its effective Curie temperature and at all times prevents a rise in the temperature of said element substantially above its effective Curie temperature.
Claim 37
Independent Claim
165 words
The method of temperature regulation comprising providing an element composed of ferromagnetic material having a permeability considerably greater than one below its effective Curie temperature and a permeability on the order of one above its effective Curie temperature, passing an electric current, of sufficient amplitude which if fed through said element for a prolonged period will heat said element well above its effective Curie temperature, to heat said element at least to a temperature high enough so that at least a part of the Curie transition takes place, sensing at least part of said Curie transition and reducing the flow of said current through said element when at least part of said Curie transition is sensed, and restoring said current to said element, said sensing and restoring steps recurring alternately to thus provide a pulsating current that holds said element at about its effective Curie temperature and at all times prevents a rise in the temperature of said element substantially above its effective Curie temperature.
Claim 38
Dependent Claim
127 words
The method of temperature regulation of claim 27, comprising: said current being an alternating current, the frequency of said alternating current being so related to the size and permeability of said element that the skin depth of the alternating current flow increases when the temperature increases into the Curie transition to thus lower the effective resistance of said element to said alternating current, whereby the power fed to said element changes during the Curie transition, said sensing step comprising sensing changes in the power of the alternating current fed to said element, to thereby sense at least part of the Curie transition during an increase in the temperature of said element and thereupon reduce the power fed to said element thereby limiting further heating of said element.
Claim 39
Dependent Claim
84 words
The method of claim 28 in which said power fed to said element includes the parameters of voltage and current one of which has less percentage variation than the other at temperatures of said element below and during the Curie transition, said sensing step including the sensing of changes in the other of said parameters to thus ascertain at least a part of the Curie transition and thereupon reduce the power fed to said element and limit the rise in temperature of said element.
Claim 40
Dependent Claim
30 words
The method of claim 29 in which the current has the smaller percentage variation, and the change in voltage is sensed to ascertain at least part of the Curie transition.
Claim 41
Dependent Claim
30 words
The method of claim 29 in which the voltage has the smaller percentage variation, and the change in current is sensed to ascertain at least part of the Curie transition.
Claim 42
Dependent Claim
42 words
The method of claim 27 in which said sensing step comprises applying magnetic induction to said element and sensing whether the element passes through at least part of the Curie transition. the element passes through at least part of the Curie transition.
Claim 43
Dependent Claim
29 words
The method of claim 27 in which said sensing step comprises detecting the change in power fed to said element due to at least part of the Curie transition.
Claim 44
Dependent Claim
19 words
The method of claim 27 in which said current is restored at a predetermined time after it is stopped.
Claim 45
Dependent Claim
29 words
The method of claim 27 in which an increase in the permeability of said element is sensed and said current is restored when such increase in permeability is sensed.
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