US4059015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Angle-to-current converter
Assignee: BA BUSINESS CREDIT Inc
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Filing: 1976-10-05
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Granted: 1977-11-22
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Expires: 1996-10-05
Abstract
Abstract An angle-to-current converter for generating an electrical current output in direct proportion to the degree of angular displacement of an input shaft. The converter includes a differential-inductance transducer constituted by a variable reluctance disc mounted on the input shaft, the profiled edge of the disc passing through diametrically-opposed air gaps defined by the cores of a pair of inductors. The profile of the disc edge is so contoured that as the disc rotates, the region of the edge lying within one gap increases while that lying within the other gap decreases, thereby varying the inductance ratio of the pair as a function of input angle. The transducer inductors are connected to the input of an astable multivibrator in a transmitter wherein the multivibrator generates a square wave whose duty cycle is varied in accordance with the varying inductance ratio and the square wave is integrated to produce a voltage whose magnitude is proportional to the input angle. This voltage is converted into a corresponding output current.
Inventors
- 👤 Toshio Satori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:31
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/05; G01F1/20; G01F1/22; G01F1/24; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/20; G01D5/2006; G01D5/202; G01D2205/00; G01D2205/70; G01D2205/77; G01D2205/776
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
24 words
An angle-to-current converter for generating an electrical current in direct proportion to the degree of angular displacement of an input shaft, said converter comprising:
Claim 2
Dependent Claim
24 words
An angle-to-current converter for generating an electrical current in direct proportion to the degree of angular displacement of an input shaft, said converter comprising:
Claim 3
Dependent Claim
121 words
A. a differential-inductance transducer constituted by a pair of inductors, each having a core defining an air gap, and variable permeability disc means mounted on said input shaft and so cooperating with said air gaps as to increase the region of the disc means lying within one gap with a change in angle as the region lying within the other gap decreases, said disc means being constituted by an edge-contoured disc, said air gaps being diametrically-opposed with respect to the edge of said disc, whereby the inductance ratio of said inductance pair varies in accordance with said angular displacement; and B. a transmitter coupled to said pair of inductors and responsive to said varying inductance ratio to generate a corresponding current.
Claim 4
Dependent Claim
121 words
A. a differential-inductance transducer constituted by a pair of inductors, each having a core defining an air gap, and variable permeability disc means mounted on said input shaft and so cooperating with said air gaps as to increase the region of the disc means lying within one gap with a change in angle as the region lying within the other gap decreases, said disc means being constituted by an edge-contoured disc, said air gaps being diametrically-opposed with respect to the edge of said disc, whereby the inductance ratio of said inductance pair varies in accordance with said angular displacement; and B. a transmitter coupled to said pair of inductors and responsive to said varying inductance ratio to generate a corresponding current.
Claim 5
Dependent Claim
34 words
A converter as set forth in claim 1, wherein said edge contour includes a step to cause said current to drop out for the first few degrees in the angular displacement of the shaft.
Claim 6
Dependent Claim
65 words
A converter as set forth in claim 1, wherein said shaft is coupled to a rotatable magnet follower magnetically linked to a permanent magnet secured to a float in a variable area tube flowmeter whereby as said float rises and falls in said tube in accordance with flow rate, said shaft is caused to turn accordingly, and said corresponding current therefore reflects said flow rate.
Claim 7
Dependent Claim
53 words
A converter as set forth in claim 1, wherein said transmitter includes an astable multivibrator whose square wave output has a duty cycle that depends on said inductance ratio, said multivibrator being formed by a pair of cross-coupled transistors, said pair of inductors being included in the respective base circuits of said transistors.
Claim 8
Dependent Claim
31 words
A converter as set forth in claim 4, further including means to integrate the square wave output of the multivibrator to produce a voltage whose magnitude depends on said inductance ratio.
Claim 9
Dependent Claim
21 words
A converter as set forth in claim 5, further including an operational amplifier to convert said voltage to said corresponding current.
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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) | 1980-11-21 | 1981-05-23 | 1981-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-21 | 1985-05-23 | 1985-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-21 | 1989-05-23 | 1989-11-22 | $7700.00 | Window Closed / Lapsed |