US3843945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature compensation of electromagnetic device
Assignee: Northrop Grumman Corp
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Filing: 1973-06-14
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Granted: 1974-10-22
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Expires: 1993-06-14
Abstract
Abstract A system for minimizing output linearity errors in an electromagnetic device which includes at least a coil. In a device such as a torquer, minimization of such errors is achieved by holding the torquer scale factor substantially constant over a temperature range by incorporating in the torquer parallel coil windings. Each coil includes one winding of material of a first temperature coefficient of resistance and a given number of turns combined in parallel with a second winding of material of a different temperature coefficient of resistance and a different number of turns.
Inventors
- 👤 M Koning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 03:20
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/06; H01F7/064
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
112 words
In an electromagnetic device having a generator of electrodynamic force which includes at least a first coil composed of material having a known temperature coefficient of resistance, said first coil having a known number of turns, apparatus for minimizing variations in said electrodynamic force caused by fluctuations of temperature over a predetermined range of temperature comprising a second coil wound in parallel with said first coil, said second coil being compressed of material having a temperature coefficient of resistance and having a number of turns different from those of said first coil, said second coil and said first coil being complementary in constant torquer scale factor over said predetermined range of temperature.
Claim 2
Dependent Claim
112 words
In an electromagnetic device having a generator of electrodynamic force which includes at least a first coil composed of material having a known temperature coefficient of resistance, said first coil having a known number of turns, apparatus for minimizing variations in said electrodynamic force caused by fluctuations of temperature over a predetermined range of temperature comprising a second coil wound in parallel with said first coil, said second coil being compressed of material having a temperature coefficient of resistance and having a number of turns different from those of said first coil, said second coil and said first coil being complementary in constant torquer scale factor over said predetermined range of temperature.
Claim 3
Dependent Claim
125 words
In an electromagnetic device as defined in claim 1, the apparatus for minimizing variations in electromagnetic force at a given temperature t wherein the temperature coefficient of resistance of the material of said first coil is Alpha and the temperature coefficient of resistance of the material of said second coil is Beta , the ratio of the number of turns of the first coil to the number of turns of the second coil is P, and the ratio of the resistance of said first coil to the resistance of said second coil at said given temperature t is Q which satisfies the equation: (P (1 + Beta t) + Q(1 + Alpha t)/(1 + Beta t) + Q(1 + Alpha t))(1 - gamma t) constant.
Claim 4
Dependent Claim
98 words
In an electromagnetic device which includes a torquer apparatus for minimizing output linearity errors over a predetermined temperature range which comprises a first coil having a first number of turns of material having a first temperature coefficient of resistance and a second coil wound in parallel with said first coil, said second coil having a second number of turns of material having a second temperature coefficient of resistance, said first and second numbers of turns and said first and second materials being of values such that said first and second coils are complementary in constant torquer scale factor.
Claim 5
Dependent Claim
98 words
In an electromagnetic device which includes a torquer apparatus for minimizing output linearity errors over a predetermined temperature range which comprises a first coil having a first number of turns of material having a first temperature coefficient of resistance and a second coil wound in parallel with said first coil, said second coil having a second number of turns of material having a second temperature coefficient of resistance, said first and second numbers of turns and said first and second materials being of values such that said first and second coils are complementary in constant torquer scale factor.
Claim 6
Dependent Claim
36 words
In an electromagnetic device as defined in claim 3, the combination wherein said first coil comprises 144 turns of No. 39 copper wire and said second coil comprises 212 turns of No. 39 coin silver wire.
Claim 7
Dependent Claim
84 words
In an electromagnetic device as defined in claim 1, the combination which includes a torquer scale of nonmagnetic material, said first coil and said second coil each being formed into three equal portions and attached symmetrically to the peripheral surface of said sleeve, three bipolar magnets being similarly symmetrically disposed within said sleeve for cooperation with turns of said coils to produce torquer and an outer case of magnetic material surrounding said sleeve and said coils to provide a return path for said magnets.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |