US3662252A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tachometer and method for obtaining a signal indicative of alternator shaft speed
Assignee: Individual
•
Filing: 1970-06-22
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Granted: 1972-05-09
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Expires: 1990-06-22
Abstract
Abstract An improved tachometer which includes an alternator connected to a shaft whose speed is to be measured and which generates an alternating voltage. Electrical circuits perform a non-linear operation on the generated alternating voltage and produce a unidirectional output proportional to the speed of the shaft by order-independent iterative pairwise binary operations. One embodiment of electrical apparatus for performing such operations is a sine wave generator followed by square law operations on the generated voltages followed by an operational summer. Another embodiment includes a square wave generator followed by bridge rectification of the square waves to produce a unidirectional signal followed by a star or tree of diodes to produce an auctioneering circuit which passes the largest rectified voltage. Another embodiment of this invention is a tachometer in which a velocity signal is derived from computations based on the alternator terminal potentials and currents.
Inventors
- 👤 Otto Joseph Mitchell Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 06:17
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/46
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
54 words
An improved tachometer for measuring the velocity of a rotating shaft comprising a multiphase alternating voltage generator coupled to the rotating shaft and adapted to generate a multiphase alternating voltage, and squaring function means for deriving from said alternating voltage an essentially ripple-free signal which is proportional to the velocity of the rotating shaft.
Claim 2
Dependent Claim
54 words
An improved tachometer for measuring the velocity of a rotating shaft comprising a multiphase alternating voltage generator coupled to the rotating shaft and adapted to generate a multiphase alternating voltage, and squaring function means for deriving from said alternating voltage an essentially ripple-free signal which is proportional to the velocity of the rotating shaft.
Claim 3
Dependent Claim
53 words
The apparatus of claim 1 wherein said means for deriving from said alternating voltage an essentially ripple-free signal comprises a multiphase squaring function means responsive to said alternating voltage for producing a unidirectional output, and means responsive to said unidirectional output for performing order-independent, iterative, pair-wise, binary operations for generating said ripple-free signal.
Claim 4
Dependent Claim
23 words
The apparatus of claim 2 wherein said means responsive to said unidirectional output for performing order-independent, iterative, pair-wise, binary operations comprises a summer.
Claim 5
Dependent Claim
34 words
The apparatus of claim 2 wherein said squaring function means comprises a star-connected square law rectifier and wherein said means responsive to said unidirectional output is the summer in said star-connected square law rectifier.
Claim 6
Dependent Claim
45 words
The apparatus of claim 1 wherein said squaring function means comprises a plurality of non-linear circuit elements producing an output signal approximately proportional to the square of the instantaneous magnitude of said alternating voltage and wherein said ripple-free signal is responsive to said output signal.
Claim 7
Dependent Claim
84 words
An improved tachometer for measuring the velocity of a rotating shaft comprising an alternating voltage generator coupled to the rotating shaft, said alternating voltage generator having a rotating flux field and multiple armature windings for generating a plurality of sinusoidal voltages, computer means for calculating a plurality of signals proportional to the squares of said sinusoidal voltages, and summer means for adding together said plurality of signals to produce a first output signal proportional to the square of the angular velocity of the shaft.
Claim 8
Dependent Claim
84 words
An improved tachometer for measuring the velocity of a rotating shaft comprising an alternating voltage generator coupled to the rotating shaft, said alternating voltage generator having a rotating flux field and multiple armature windings for generating a plurality of sinusoidal voltages, computer means for calculating a plurality of signals proportional to the squares of said sinusoidal voltages, and summer means for adding together said plurality of signals to produce a first output signal proportional to the square of the angular velocity of the shaft.
Claim 9
Dependent Claim
37 words
The apparatus of claim 6 including means responsive to said first output signal for calculating the square root of said first output signal to produce a second output signal proportional to the angular velocity of the shaft.
Claim 10
Dependent Claim
27 words
The apparatus of claim 6 including dynamic filter means energized by said sinusoidal voltages and adapted to deliver filter signals to which said computer means are responsive.
Claim 11
Dependent Claim
13 words
The apparatus of claim 8 wherein said dynamic filters are low pass filters.
Claim 12
Dependent Claim
14 words
The apparatus of claim 8 wherein said dynamic filter means are high pass filters.
Claim 13
Dependent Claim
18 words
The apparatus of claim 8 wherein said dynamic filter means includes both low pass and high pass filters.
Claim 14
Dependent Claim
74 words
The apparatus of claim 6 in which said armature windings carry terminal currents and produce terminal voltages and including means for conducting secondary currents proportional to said terminal currents through a plurality of impedences, means for producing a plurality of secondary voltages proportional to said terminal voltages, and means for adding respectively said plurality of secondary voltages to the voltage drops in said plurality of impedences to generate the said plurality of sinusoidal voltages.
Claim 15
Dependent Claim
11 words
The apparatus of claim 12 in which said impedances are resistances.
Claim 16
Dependent Claim
11 words
The apparatus of claim 12 in which said impedAnces are inductances.
Claim 17
Dependent Claim
138 words
An improved tachometer for measuring the angular velocity of a rotating rotor comprising an alternating voltage generator coupled to said rotor, said generator having a magnetic field and an armature winding whose terminals have a terminal sinusoidal voltage and whose winding carries a terminal current through the winding impedance, computer means for calculating a first signal voltage responsive to said terminal voltage, means for calculating a second signal voltage responsive to said terminal current and proportional to the product of said terminal current times said winding impedance, means for generating a third signal voltage with both phase and frequency proportional respectively to the angular phase and frequency of rotation of said magnetic field by adding said first and second signal voltages, and means for computing an output signal responsive to the angular frequency of said third signal voltage.
Claim 18
Dependent Claim
138 words
An improved tachometer for measuring the angular velocity of a rotating rotor comprising an alternating voltage generator coupled to said rotor, said generator having a magnetic field and an armature winding whose terminals have a terminal sinusoidal voltage and whose winding carries a terminal current through the winding impedance, computer means for calculating a first signal voltage responsive to said terminal voltage, means for calculating a second signal voltage responsive to said terminal current and proportional to the product of said terminal current times said winding impedance, means for generating a third signal voltage with both phase and frequency proportional respectively to the angular phase and frequency of rotation of said magnetic field by adding said first and second signal voltages, and means for computing an output signal responsive to the angular frequency of said third signal voltage.
Claim 19
Dependent Claim
24 words
The apparatus of claim 15 in which said armature winding is multiphase, said terminal voltage is multiphase, and said third signal voltage is multiphase.
Claim 20
Dependent Claim
16 words
The apparatus of claim 15 in which said magnetic field is produced by a permanent magnet.
Claim 21
Dependent Claim
17 words
The apparatus of claim 15 in which said magnetic field is produced by a direct-current excitation winding.
Claim 22
Dependent Claim
27 words
The apparatus of claim 15 in which said means for computing an output signal comprises a frequency meter responsive to the frequency of said third signal voltage.
Claim 23
Dependent Claim
47 words
The apparatus of claim 15 in which said means for computing an output signal comprises filter means responsive to said third signal voltage to produce a fourth signal voltage, and combining means responsive to both said third and said fourth signal voltages to produce said output signal.
Claim 24
Dependent Claim
161 words
An improved tachometer for measuring the velocity of a rotating rotor comprising an alternating voltage generator coupled to the rotating rotor, said generator having an exciting field and multiple armature windings, said multiple armature windings having winding impedances carrying terminal currents and having terminal sinusoidal voltages, means for conducting secondary currents proportional to said terminal currents through a plurality of impedances proportional to said winding impedances to produce a plurality of voltage drops, means for producing a plurality of secondary voltages proportional to said terminal sinusoidal voltages respectively, means for producing a plurality of computed sinusoidal voltages proportional to the addition respectively of said plurality of voltage drops to said plurality of secondary voltages, said computed sinusoidal voltages having both phase and frequency proportional respectively to the angular phase and frequency of rotation of said exciting field, and means responsive to the angular frequency of said computed voltages to deliver an output signal responsive to the angular velocity of said rotor.
Claim 25
Dependent Claim
161 words
An improved tachometer for measuring the velocity of a rotating rotor comprising an alternating voltage generator coupled to the rotating rotor, said generator having an exciting field and multiple armature windings, said multiple armature windings having winding impedances carrying terminal currents and having terminal sinusoidal voltages, means for conducting secondary currents proportional to said terminal currents through a plurality of impedances proportional to said winding impedances to produce a plurality of voltage drops, means for producing a plurality of secondary voltages proportional to said terminal sinusoidal voltages respectively, means for producing a plurality of computed sinusoidal voltages proportional to the addition respectively of said plurality of voltage drops to said plurality of secondary voltages, said computed sinusoidal voltages having both phase and frequency proportional respectively to the angular phase and frequency of rotation of said exciting field, and means responsive to the angular frequency of said computed voltages to deliver an output signal responsive to the angular velocity of said rotor.
Claim 26
Independent Claim
51 words
A method for measuring the velocity of a rotating shaft comprising the steps of generating a multiphase alternating voltage by means coupled to the rotating shaft and deriving from said multiphase alternating voltage with a squaring operation an essentially ripple-free signal which is related to the velocity of the rotating shaft.
Claim 27
Independent Claim
51 words
A method for measuring the velocity of a rotating shaft comprising the steps of generating a multiphase alternating voltage by means coupled to the rotating shaft and deriving from said multiphase alternating voltage with a squaring operation an essentially ripple-free signal which is related to the velocity of the rotating shaft.
Claim 28
Dependent Claim
38 words
The method of claim 22 in which said step of deriving from said alternating voltage an essentially ripple-free signal includes the step of performing order-independent, iterative, pair-wise binary operations on said alternating voltage for generating said ripple-free signal.
Claim 29
Dependent Claim
48 words
The method of claim 22 in which said step of deriving from said alternating voltage an essentially ripple-free signal includes the steps of squaring each phase of said alternating voltage to produce a plurality of squared signals and operationally summing said squared signals to form said ripple-free signal.
Claim 30
Independent Claim
122 words
A method for measuring the velocity of a rotating shaft comprising the steps of generating an alternating voltage and an alternating current by means having a magnetic field and armature windings and coupled to the rotating shaft, deriving a first signal voltage from said alternating voltage, deriving a second signal voltage from said alternating current which is proportional to a product of the alternating current times winding impedances, adding said first and second signal voltages to produce a third signal voltage having both phase and frequency proportional respectively to the angular phase and frequency of rotation of said magnetic field, and measuring the frequency of said third signal voltage to produce an output signal proportional to the velocity of the rotating shaft.
Claim 31
Independent Claim
122 words
A method for measuring the velocity of a rotating shaft comprising the steps of generating an alternating voltage and an alternating current by means having a magnetic field and armature windings and coupled to the rotating shaft, deriving a first signal voltage from said alternating voltage, deriving a second signal voltage from said alternating current which is proportional to a product of the alternating current times winding impedances, adding said first and second signal voltages to produce a third signal voltage having both phase and frequency proportional respectively to the angular phase and frequency of rotation of said magnetic field, and measuring the frequency of said third signal voltage to produce an output signal proportional to the velocity of the rotating shaft.
References Cited (Backward Citations)
US3110817A
Cited
US3408556A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |