Patent EP0107927A1 successfully refreshed from Google Patents.
EP0107927A1
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Autoregulating electrically shielded heater
Assignee: Metcal Inc
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Filing: 1983-09-30
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Granted: —
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Expires: 2003-09-30
Abstract
Abstract An autoregulating, electrically shielded heater employs a laminated structure having two magnetic alloy permeable materials of widely differing Curie point temperatures and preferably of differing resistivities. A constant current supply is connected across the laminate such that current flows in the laminae along parallel paths. Due to skin effect, the current is confined to a thin region of a first lamina which is located between the other lamina and the electrical return path. This first lamina has the lower Curie temperature and preferably the higher resistivity of the two laminae to produce heating proportional to | 2 R 1 . When the Curie temperature of the first lamina is approached, the current spreads into the other lamina which may have a lower resistivity and higher Curie temperature and heating is obtained by | 2 R 2 where l 2 is a constant due to the constant current source and preferably R 2 <R,. Thus, power is reduced and temperature is maintained at or about the Curie temperature of the first layer. The high permeability of the second lamina prohibits the current from penetrating deeply into the second laminae whereby a low frequency power supply may be used without radiation of the electro- magnetic field.
Inventors
- 👤 John F. Krumme
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 22:29
CPC Classifications
B; B23; B23K; B23K3/00; B23K3/04; B23K3/047; B23K3/0475
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
56 words
An element for an autoregulating heating device comprising: a laminated structure having at least a first lamina and a second lamina, both being a material having a high magnetic permeability, said first lamina being of a material having a lower Curie temperature than said second lamina, said laminae being in electrical contact along their adjacent surfaces.
Claim 2
Dependent Claim
56 words
An element for an autoregulating heating device comprising: a laminated structure having at least a first lamina and a second lamina, both being a material having a high magnetic permeability, said first lamina being of a material having a lower Curie temperature than said second lamina, said laminae being in electrical contact along their adjacent surfaces.
Claim 3
Dependent Claim
32 words
- - - 2. The element according to claim 1 wherein the resistivity of said first lamina is in the range of two to ten times the resistivity of said second lamina.
Claim 4
Dependent Claim
20 words
The element according to claim 1 or claim 2 wherein one of said laminae surrounds the other of said laminae.
Claim 5
Dependent Claim
49 words
An autoregulating heating device including the element of claim 1 or claim 2 and comprising: a constant current alternating current source, said element adapted to be connected across said source such that the current paths through said laminae are in parallel and parallel to the interface between said laminae.
Claim 6
Dependent Claim
18 words
The element according to claim 4 wherein said source operates at a frequency of at least 50 Hz.
Claim 7
Dependent Claim
79 words
A soldering iron having a heating element including the element of claim 1 wherein: said first lamina is a hollow cylindrical member, said second lamina is a hollow cylindrical member coaxial with and having an inner surface surrounding said first lamina and in electrical contact therewith, and a conductive member extending coaxial of and within said first lamina, one end of said conductive rod in electrical contact with said laminae at one and the same end of said cylinders.
Claim 8
Dependent Claim
27 words
The device according to claim 6 further comprising: a constant current source connected across said rod and said element remote from said one end of said rod.
Claim 9
Dependent Claim
72 words
A structure comprising: a first member of a-material having a high magnetic permeability, a second member of a material having a high magnetic permeability, said first member having a lower Curie point than said second member, said members contacting one another over a coextensive length of each, and said members adapted to have an alternating, constant current source connected across a coextensive length of said member to induce parallel flow currents therein.
Claim 10
Dependent Claim
72 words
A structure comprising: a first member of a-material having a high magnetic permeability, a second member of a material having a high magnetic permeability, said first member having a lower Curie point than said second member, said members contacting one another over a coextensive length of each, and said members adapted to have an alternating, constant current source connected across a coextensive length of said member to induce parallel flow currents therein.
Claim 11
Dependent Claim
41 words
An autoregulating heating device including the structure of claim 8 and further including an alternating current, constant current source of a frequency in a range of approximately 50 Hz and higher, means connecting said source across said lengths of said members.
Claim 12
Independent Claim
59 words
The method of autoregulating the temperature of a heater of small size at low frequencies comprising the steps of providing a laminated structure having at least first and second layers of high magnetic permeability material having different Curie temperatures, and. applying.a constant current alternating current across the laminated structure to cause current to flow in parallel in the laminae.
Claim 13
Independent Claim
59 words
The method of autoregulating the temperature of a heater of small size at low frequencies comprising the steps of providing a laminated structure having at least first and second layers of high magnetic permeability material having different Curie temperatures, and. applying.a constant current alternating current across the laminated structure to cause current to flow in parallel in the laminae.
Claim 14
Dependent Claim
33 words
The element according to claim 1 or claim 6 wherein said second lamina has a thickness equal to at least three skin depths in said second lamina at operating frequency of said element.
Claim 15
Dependent Claim
30 words
The element according to claim 4 wherein said second lamina has a thickness equal to at least three skin depths in said second lamina at operating frequency of said element.
References Cited (Backward Citations)
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