US4188623A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature responsive apparatus employing a thermocouple
Assignee: Hitachi Ltd
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Filing: 1977-07-28
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Granted: 1980-02-12
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Expires: 1997-07-28
Abstract
Abstract A temperature responsive apparatus includes a thermocouple producing a thermoelectric e.m.f. depending on the temperature difference between a temperature to be detected and a circumferential temperature and a first winding supplied with current from the thermocouple to generate a first magnetic field. A second winding is connected to a voltage source to generate a second magnetic field in the opposite direction to that generated by the first winding and a reed switch is positioned in the total magnetic field generated by the first and the second windings so as to respond to the intensity of the total magnetic field to make and break its contacts. A diode is also connected to the voltage source, and the second winding is always excited in accordance with the voltage drop across the diode to maintain said second magnetic field.
Inventors
- 👤 Seiko Suzuki
- 👤 Masahiro Takasaka
- 👤 Toru Sugawara
- 👤 Toru Takahasi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:10
CPC Classifications
G; G01; G01K; G01K3/00; G01K3/005; G01K7/00; G01K7/02; G01K7/021; G01K7/10; G01K7/12; G01K7/13
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
148 words
A temperature responsive apparatus comprising a voltage source, a thermocouple producing a thermoelectric e.m.f. depending on the temperature difference between the temperature to be detected and the circumferential temperature, a first winding supplied with current from the thermocouple to generate a first magnetic field, a second winding generating a second magnetic field in the opposite direction to that generated by said first winding, and a reed switch positioned in the total magnetic field generated by said first and second windings and responding to the intensity of the total magnetic field to make and break its contacts, and at least one diode connected to said voltage source for providing a voltage drop thereacross which varies in dependence on changes in the circumferential temperature, said second winding being connected in parallel to said diode so as to be excited in accordance with variations in said voltage drop across said diode.
Claim 2
Dependent Claim
148 words
A temperature responsive apparatus comprising a voltage source, a thermocouple producing a thermoelectric e.m.f. depending on the temperature difference between the temperature to be detected and the circumferential temperature, a first winding supplied with current from the thermocouple to generate a first magnetic field, a second winding generating a second magnetic field in the opposite direction to that generated by said first winding, and a reed switch positioned in the total magnetic field generated by said first and second windings and responding to the intensity of the total magnetic field to make and break its contacts, and at least one diode connected to said voltage source for providing a voltage drop thereacross which varies in dependence on changes in the circumferential temperature, said second winding being connected in parallel to said diode so as to be excited in accordance with variations in said voltage drop across said diode.
Claim 3
Dependent Claim
32 words
The temperature responsive apparatus of claim 1, characterized in that said diode is connected to said voltage source through a resistor and the reed switch is connected in parallel to said resistor.
Claim 4
Dependent Claim
39 words
The temperature responsive apparatus of claim 1, characterized in that said diode is connected to said voltage source through a resistor and the reed switch is connected in parallel to the series connection of said diode and said resistor.
Claim 5
Dependent Claim
26 words
The temperature responsive apparatus of claim 1, further comprising compensating circuit means for applying additional current to said second winding when said reed switch is closed.
Claim 6
Dependent Claim
55 words
The temperature responsive apparatus of claim 4, characterized in that said compensating circuit means comprises a further diode connected in series with said reed switch and through which current flows when said reed switch is closed and means for adding the voltage drop across said further diode to the voltage drop across said first-recited diode.
Claim 7
Dependent Claim
37 words
The temperature responsive apparatus of claim 5, characterized in that a thermistor is connected with said further diode and the voltage drop across said further diode is regulated by said thermistor in accordance with the circumferential temperature.
Claim 8
Dependent Claim
33 words
The temperature responsive apparatus of claim 1, further comprising means for generating a bias magnetic field through said reed switch in the same direction as the magnetic field generated by said first winding.
Claim 9
Dependent Claim
25 words
The temperature responsive apparatus of claim 7, characterized in that said bias magnetic field generating means comprises a permanent magnet disposed beside said reed switch.
Claim 10
Dependent Claim
160 words
A temperature responsive apparatus comprising a thermocouple producing a thermoelectric e.m.f. depending on the temperature difference between the temperature to be detected and the circumferential temperature, a first winding connected to said thermocouple to generate a first magnetic field, a second winding disposed to generate a second magnetic field in the opposite direction to that generated by said first winding, a reed switch positioned in the total magnetic field generated by said first and second windings and being responsive to the intensity of said total magnetic field to make and break its contacts, indicator means for providing a visual or audible indication, a voltage source, a diode connected in series with said reed switch and said indicator means across said voltage source, a first resistor connected across said reed switch, and a second resistor connected in series with said second winding across said diode, said diode providing a variable voltage drop thereacross in dependence upon changes in the circumferential temperature.
Claim 11
Dependent Claim
160 words
A temperature responsive apparatus comprising a thermocouple producing a thermoelectric e.m.f. depending on the temperature difference between the temperature to be detected and the circumferential temperature, a first winding connected to said thermocouple to generate a first magnetic field, a second winding disposed to generate a second magnetic field in the opposite direction to that generated by said first winding, a reed switch positioned in the total magnetic field generated by said first and second windings and being responsive to the intensity of said total magnetic field to make and break its contacts, indicator means for providing a visual or audible indication, a voltage source, a diode connected in series with said reed switch and said indicator means across said voltage source, a first resistor connected across said reed switch, and a second resistor connected in series with said second winding across said diode, said diode providing a variable voltage drop thereacross in dependence upon changes in the circumferential temperature.
Claim 12
Dependent Claim
39 words
The temperature responsive apparatus of claim 9, further comprising compensating means connecting one end of said second winding to one side of said reed switch for applying additional current to said second winding when said reed switch is closed.
Claim 13
Dependent Claim
55 words
The temperature responsive apparatus of claim 10, characterized in that said compensating circuit means comprises a further diode connected in series with said reed switch and through which current flows when said reed switch is closed and means for adding the voltage drop across said further diode to the voltage drop across said first-recited diode.
Claim 14
Dependent Claim
50 words
The first-recited apparatus of claim 10, wherein said compensating circuit means comprises a further diode connected in series between reed switch and said temperature responsive diode and a thermistor connected between one side of said reed switch and the point of connection of said second resistor and said second winding.
Claim 15
Dependent Claim
18 words
The temperature responsive apparatus of claim 12, wherein a third resistor is connected in parallel to said thermistor.
Claim 16
Dependent Claim
33 words
The temperature responsive apparatus of claim 11, further comprising means for generating a bias magnetic field through said reed switch in the same direction as the magnetic field generated by said first winding.
Claim 17
Dependent Claim
25 words
The temperature responsive apparatus of claim 14, characterized in that said bias magnetic field generating means comprises a permanent magnet disposed beside said reed switch.
Claim 18
Dependent Claim
163 words
A temperature responsive apparatus comprising a thermocouple producing a thermoelectric e.m.f. depending on the temperature difference between the temperature to be detected and the circumferential temperature, a first winding connected to said thermocouple to generate a first magnetic field, a second winding disposed to generate a second magnetic field in the opposite direction to that generated by said first winding, a reed switch positioned in the total magnetic field generated by said first and second windings and being responsive to the intensity of said total magnetic field to make and break its contacts, indicator means for providing a visual or audible indication, a voltage source, said reed switch and said indicator means being connected in series across said voltage source, a diode and a first resistor connected in series across said reed switch, and a second resistor connected in series with said second winding across said diode, said diode providing a variable voltage drop thereacross in dependence upon changes in the circumferential temperature.
Claim 19
Dependent Claim
163 words
A temperature responsive apparatus comprising a thermocouple producing a thermoelectric e.m.f. depending on the temperature difference between the temperature to be detected and the circumferential temperature, a first winding connected to said thermocouple to generate a first magnetic field, a second winding disposed to generate a second magnetic field in the opposite direction to that generated by said first winding, a reed switch positioned in the total magnetic field generated by said first and second windings and being responsive to the intensity of said total magnetic field to make and break its contacts, indicator means for providing a visual or audible indication, a voltage source, said reed switch and said indicator means being connected in series across said voltage source, a diode and a first resistor connected in series across said reed switch, and a second resistor connected in series with said second winding across said diode, said diode providing a variable voltage drop thereacross in dependence upon changes in the circumferential temperature.
Claim 20
Dependent Claim
39 words
The temperature responsive apparatus of claim 16, further comprising compensating means connecting one end of said second winding to one side of said reed switch for applying additional current to said second winding when said reed switch is closed.
Claim 21
Dependent Claim
55 words
The temperature responsive apparatus of claim 17, characterized in that said compensating circuit means comprises a further diode connected in series with said reed switch and through which current flows when said reed switch is closed and means for adding the voltage drop across said further diode to the voltage drop across said first-recited diode.
Claim 22
Dependent Claim
52 words
The temperature responsive apparatus of claim 17, wherein said compensating means comprises a further diode connected in series with said reed switch, and a thermistor connected between the point of connection of said reed switch and said further diode and the point of connection of said second resistor and said second winding.
Claim 23
Dependent Claim
18 words
The temperature responsive apparatus of claim 19, wherein a third resistor is connected in parallel to said thermistor.
Claim 24
Dependent Claim
33 words
The temperature responsive apparatus of claim 16, further comprising means for generating a bias magnetic field through said reed switch in the same direction as the magnetic field generated by said first winding.
Claim 25
Dependent Claim
25 words
The temperature responsive apparatus of claim 21, characterized in that said bias magnetic field generating means comprises a permanent magnet discposed beside said reed switch.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-02-11 | 1983-08-13 | 1984-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-11 | 1987-08-13 | 1988-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-11 | 1991-08-13 | 1992-02-12 | $7700.00 | Window Closed / Lapsed |