US4326419A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromechanical pressure transducer
Assignee: Robert Bosch GmbH
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Filing: 1980-02-19
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Granted: 1982-04-27
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Expires: 2000-02-19
Abstract
Abstract An electromechanical transducer for transforming pressure fluctuations into varying electrical signals, especially for use as the induction tube pressure sensor for an internal combustion engine. A Hall-effect sensor moves within a local magnetic field to detect changes in pressure which alter the configuration of a diaphragm or diaphragm bellows to which the Hall-generator is attached. In order to suppress temperature-dependent terms in the Hall voltage equation, the invention provides for periodically alternating energization of the electromagnets, i.e., for alternation or alternating shut-off of the magnetic field. The Hall voltages measured during the two states of the magnetic field are subtracted from one another, thereby eliminating the temperature-dependent term. A number of configurations of the transducer elements is presented.
Inventors
- 👤 Werner Herden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:04
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0082; G01L9/0085; G01L9/0041; G01L9/007; G01L9/14
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
170 words
A transducer system for generating a pressure-dependent electrical output signal having a housing (1) including therein at least one deformable diaphragm (5) subjected to a variable pressure and deflecting along a predetermined deflection axis; at least one electromagnet (13; 16, 17; 20-23) for generating a magnetic field along said axis, when energized; a Hall-effect sensor (9) located along said axis and secured to the membrane to obtain an output signal from the Hall-effect sensor as a function of the position of said Hall effect sensor in said magnetic field; means (60, 70) to discontinuously energize the electromagnet in a predetermined polarity to thereby generate a field of discontinuous predetermined polarity to which said Hall-effect sensor is subjected; and means (80) to evaluate the output signal of said Hall-effect sensor at the time of energization in said predetermined direction with respect to the signal absent energization in said predetermined direction to derive an output signal therefrom and thereby to eliminate the effect of temperature on the output signal from the system.
Claim 2
Dependent Claim
170 words
A transducer system for generating a pressure-dependent electrical output signal having a housing (1) including therein at least one deformable diaphragm (5) subjected to a variable pressure and deflecting along a predetermined deflection axis; at least one electromagnet (13; 16, 17; 20-23) for generating a magnetic field along said axis, when energized; a Hall-effect sensor (9) located along said axis and secured to the membrane to obtain an output signal from the Hall-effect sensor as a function of the position of said Hall effect sensor in said magnetic field; means (60, 70) to discontinuously energize the electromagnet in a predetermined polarity to thereby generate a field of discontinuous predetermined polarity to which said Hall-effect sensor is subjected; and means (80) to evaluate the output signal of said Hall-effect sensor at the time of energization in said predetermined direction with respect to the signal absent energization in said predetermined direction to derive an output signal therefrom and thereby to eliminate the effect of temperature on the output signal from the system.
Claim 3
Dependent Claim
28 words
System according to claim 1, wherein said means for discontinuously energizing the electromagnet comprises a source (70, 60) for providing a periodically alternating energization current for said magnet.
Claim 4
Dependent Claim
17 words
A transducer system according to claim 2, wherein said current source (60) generates a square wave current.
Claim 5
Dependent Claim
18 words
A transducer system according to claim 2, wherein said current source (70) generates a periodically alternating wave current.
Claim 6
Dependent Claim
39 words
System according to claim 1, wherein the evaluation means comprises means (80) for generating the difference of signals obtained during different states of energization of said electromagnet to obtain an electrical output signal in which temperature-dependent terms are absent.
Claim 7
Dependent Claim
34 words
A transducer system according to claim 1, wherein said at least one magnet is two electromagnets so disposed that identical magnetic poles are adjacent to one another and said Hall-effect sensor is disposed therebetween.
Claim 8
Dependent Claim
17 words
A transducer system according to claim 1, wherein said Hall-effect sensor is attached to said deformable diaphragm.
Claim 9
Dependent Claim
20 words
A transducer system according to claim 1, wherein said at least one magnet is stationary with respect to said housing.
Claim 10
Dependent Claim
47 words
A transducer system according to claim 1, wherein said at least one deformable diaphragm is a double-walled diaphragm bellows, one wall of which is stationary with respect to said housing and the other wall of which is movable subject to said pressure and supports said Hall-effect sensor.
Claim 11
Dependent Claim
20 words
System according to claim 1, wherein said energization means (60) provides unidirectional sequential pulses to the at least one electromagnet.
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) | 1985-04-26 | 1985-10-26 | 1986-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-26 | 1989-10-26 | 1990-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-26 | 1993-10-26 | 1994-04-27 | $7700.00 | Window Closed / Lapsed |