US4039931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System to sense a marker on a rotating body
Assignee: Robert Bosch GmbH
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Filing: 1976-07-06
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Granted: 1977-08-02
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Expires: 1996-07-06
Abstract
Abstract To accurately determine the position of a marker on a rotating disk, for example coupled to the crankshaft of an automotive engine to determine the angular position thereof, an inductive transducer picks up the field generated by a permanent magnet located on the disk and, to compensate for amplitude variations in the output due to speed changes of the disk, and eliminate the effects of spurious side lobes generated by reversely positioned magnets, the amplitude of the output signal is normalized in an amplifier which includes a non-linear input circuit. The non-linear input circuit, preferably, is a diode-resistor network, in which the diode is forwardly poled, and a controlled current is supplied to the diode, the control being effected by the output of the amplifier in a feedback circuit, so that the output obtained from the amplifier will be uniform regardless of change in speed of the rotating body, and hence change in amplitude of the voltage induced in the inductive pick-up.
Inventors
- 👤 Hartmut Schweizer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:49
CPC Classifications
F; F02; F02P; F02P7/00; F02P7/06; F02P7/067; F02P7/0675; G; G01; G01D; G01D5/00; G01D5/12; G01M; G01M15/00; G01M15/04; G01M15/06
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
87 words
System to sense a marker on a rotating body (10) comprising a permanent magnet (11-14) located on the rotatng body and forming said marker; an inductive transducer (15) fixedly located with respect to the rotating body and having a voltage induced therein upon rotation of the body; and an amplitude control circuit (16) connected to the transducer (15) and including a feedback network to normalize the amplitude of the output from said control circuit (16) to an essentially constant value independent of speed of the rotating body.
Claim 2
Dependent Claim
87 words
System to sense a marker on a rotating body (10) comprising a permanent magnet (11-14) located on the rotatng body and forming said marker; an inductive transducer (15) fixedly located with respect to the rotating body and having a voltage induced therein upon rotation of the body; and an amplitude control circuit (16) connected to the transducer (15) and including a feedback network to normalize the amplitude of the output from said control circuit (16) to an essentially constant value independent of speed of the rotating body.
Claim 3
Dependent Claim
31 words
System according to claim 1, wherein a plurality of markers (11-14) are located on the rotating body, the markers comprising permanent magnets of alternating magnetic polarity facing the inductive transducer (15).
Claim 4
Dependent Claim
42 words
System according to claim 1, wherein the amplitude control circuit (16) comprises an essentially linear amplifier (22, 22') and a non-linear input circuit (20, 21, 24) connected to the amplifier, the output (17) of the amplifier providing the output of the system.
Claim 5
Dependent Claim
16 words
System according to claim 3, wherein the non-linear input circuit comprises a diode-resistor combination (20, 21).
Claim 6
Dependent Claim
13 words
System according to claim 3, wherein the feedback network includes a rectifier (23).
Claim 7
Dependent Claim
31 words
System according to claim 4, wherein one of the elements of the combination of the diode-resistor combination (20, 21) is connected in parallel to the input of the amplifier (22, 22').
Claim 8
Dependent Claim
48 words
System according to claim 4, further comprising means (24) to supply a current of controlled amplitude to the diode (20), said current supply means (24) being included in the feedback network and being controlled by the output of said amplifier, the diode being poled to pass said current.
Claim 9
Dependent Claim
37 words
System according to claim 7, further comprising a rectifier (23; 37, 36, 38) forming part of the feedback network from the output of the amplifier (22, 22') to the current source (24; 40, 39, 42, 45, 46).
Claim 10
Dependent Claim
98 words
System according to claim 3, wherein the non-linear input circuit comprises a voltage divider including a non-linear resistance element (20) having a variable resistance, the resistance varying in dependence on current supplied thereto; and means (24; 40, 39, 42, 46, 45) supplying a variable current to said non-linear element (20), said means being controlled by the output of the amplifier (22, 22') to supply a current of such magnitude to flow through the non-linear element (20) that the output of the amplifier (22, 22') remains essentially constant regardless of amplitude of the output from the inductive transducer (15).
Claim 11
Dependent Claim
40 words
System according to claim 9, further comprising a rectifier circuit (23; 37, 36, 38) connected in the feed-back network from the amplifier (22, 22') to the current source (24; 40, 39, 42, 46, 45) and to the non-linear element (20).
Claim 12
Dependent Claim
44 words
In an automotive engine, a system to determine the angular position of the crankshaft of the engine, comprising a disk-shaped element (10) coupled to the crankshaft, and further comprising p1 the system of claim 1 wherein the disk-shaped element forms the rotating body (10).
Claim 13
Dependent Claim
70 words
In an automotive engine, a system to determine the angular position of the crankshaft of the engine, comprising a disk-shaped element (10) coupled to the crankshaft, and further comprising the system of claim 9 wherein the disk-shaped element forms the rotating body (10) and wherein a plurality of markers (11-14) are located on the rotating body, the markers comprising permanent magnets of alternating magnetic polarity facing the inductive transducer (15).
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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) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |