Method and apparatus for providing multiple autoregulated temperatures
AssigneeElectric Power Research Institute, Inc.
InventorsStephen M. Jacobs, Cristian Filimon
Life of this patent
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Abstract
The present invention generally relates to use of constant current power supply to control temperatures of a device to plural Curie temperatures, without sacrificing the precision and uniformity of temperature achieved in the known devices. In accordance with exemplary embodiments, multiple layers of alloy having different Curie temperatures are separately accessed as an outer most layer is heated through its Curie point. Power to the device can be controlled by varying a frequency of circulating current and by searching to identify a layer of Curie point material which provides heating at a temperature accurately controlled to a fixed value, where any one of a number of different such temperatures may be selected.
Claims23
Apparatus for generating heat comprising:
- means for generating a relatively constant current;
- and
- means for selectively producing heat at any one of plural relatively constant temperatures in response to said constant current generating means, based on reflected resistance of said heat producing means, said heat producing means including:
- a core having at least one electrically conductive, non-magnetic material;
- and
- at least two layers of magnetic material, a first of said at least two layers having a first Curie temperature and a second of said at least two layers having a second Curie temperature different from said first Curie temperature, said core being cooperatively arranged with said first layer and said second layer to selectively produce heat at said first Curie temperature and said second Curie temperature.
A heater formed as a structure comprising:
- at least one electrically conductive, non-magnetic material having at least a first side;
- and
- at least two layers of magnetic material arranged on said first side, a first of said at least two layers having a first Curie temperature and a second of said at least two layers having a second Curie temperature different from said first Curie temperature, said at least one electrically conductive, non-magnetic material being cooperatively arranged with said first layer and said second layer to establish first and second operating points, as a function of reflected resistance, which selectively produce heat at said first Curie temperature and said second Curie temperature.
An apparatus for generating a heat supply comprising:
- means for selectively producing heat at any one of plural relatively constant temperature operating points of a multilayer structure, each of said operating points being produced by a separate material having a Curie temperature which corresponds to one of said plural constant temperature operating points of said multilayer structure;
- and
- means for controlling said heat producing means at one of said operating points as a function of reflected resistance of the heat producing means.
Method for generating a heat supply comprising the steps of:
- selectively producing heat at any one of plural relatively constant temperature operating points of a multilayer structure, each of said operating points being produced by a separate material having a Curie temperature which corresponds to one of said plural constant temperature operating points of said multilayer structure;
- and
- controlling said separate Curie temperature materials at one of said operating points as a function of reflected resistance during selective heat production.
Dependencies are inferred from the claim text.