US3618073A
Expired / Lapsed
US
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Synchro angle converter
Assignee: Lockheed Martin Tactical Systems Inc
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Filing: 1970-03-23
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Granted: 1971-11-02
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Expires: 1990-03-23
Abstract
Abstract A synchro converter demodulates the stator signals, selects stator signal relationships indicative of a rotor-to-stator angular sector through logic switching, converts the selected signals in analog form to digital equivalents, and digitally processes the resultant signals to obtain an output representative of the synchro rotor-to-stator angular position.
Inventors
- 👤 Stephen J Domchick
- 👤 Howard M Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:14
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/64; H03M1/645
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
169 words
A synchro angle-to-digital converter for measuring the rotorto-stator angular relationship comprising: a. first circuit means coupled to the synchro rotor signal and the stator signals to provide demodulated stator signal outputs; b. logic circuit means coupled to the first circuit means and accepting the demodulated stator signals to provide signal outputs on a first channel representative of a particular rotor-to-stator angular sector and on a second channel signals defining the sector; c. second circuit means coupled to and accepting the demodulated stator output to provide a unique pair of demodulated stator signals determined in accordance with the logic circuit means first channel output; d. analog-to-digital converter means coupled to the second circuit means output to provide a digital output signal representative of the voltage ratio of the demodulated stator signal pair; and e. digital processor means coupled to and accepting the outputs of the analog-to-digital converter means and the second channel of the logic circuit means to provide an output digital signal indicative of the synchro rotor-to-stator angular position.
Claim 2
Dependent Claim
169 words
A synchro angle-to-digital converter for measuring the rotorto-stator angular relationship comprising: a. first circuit means coupled to the synchro rotor signal and the stator signals to provide demodulated stator signal outputs; b. logic circuit means coupled to the first circuit means and accepting the demodulated stator signals to provide signal outputs on a first channel representative of a particular rotor-to-stator angular sector and on a second channel signals defining the sector; c. second circuit means coupled to and accepting the demodulated stator output to provide a unique pair of demodulated stator signals determined in accordance with the logic circuit means first channel output; d. analog-to-digital converter means coupled to the second circuit means output to provide a digital output signal representative of the voltage ratio of the demodulated stator signal pair; and e. digital processor means coupled to and accepting the outputs of the analog-to-digital converter means and the second channel of the logic circuit means to provide an output digital signal indicative of the synchro rotor-to-stator angular position.
Claim 3
Dependent Claim
70 words
The synchro angle-to-digital converter of claim 1 wherein the first circuit means comprises: a. an amplifier accepting the synchro stator signals to buffer the converter from the synchro and to scale the stator signals to a level suitable to the converter; and b. a phase sensitive demodulator accepting the rotor signal from the synchro and the scaled stator signals from the amplifier to provide demodulated stator signals at its output.
Claim 4
Dependent Claim
122 words
The synchro angle-to-digital converter of claim 2 wherein the phase sensitive demodulator comprises: a. a phase shift and signal shaping circuit accepting the synchro rotor signal to provide a substantially square wave output signal shifted in phase such that the signal zero crossover coincides with the stator signal peaks; b. a one-shot coupled to the output of the phase shift and signal shaping circuit to trigger a pulse at the stator signal peaks; and c. a sample-and-hold circuit coupled to and accepting the output pulse of the one shot to trigger tracking of the stator signals on the leasing edge of the pulse, holding of the stator signal levels during the pulse, and tracking cutoff on the trailing edge of the pulse.
Claim 5
Dependent Claim
29 words
The synchro angle-to-digital converter of claim 1 wherein the analog-to-digital converter means is a successive approximation-comparison converter outputting a digital signal representative of the ratio of two stator signals.
Claim 6
Dependent Claim
77 words
The synchro angle-to-digital converter of claim 1 wherein the digital processor comprises: a. a read-only memory connected to accept the output signal of the analog-to-digital converter means as an address to a store of resultant calculations for the arctangent series to provide a digital signal output indicative of an angular position; and b. an adder/subtracter circuit connected to accept the outputs of the read-only memory and the logic circuit means second channel to algebraically combine said outputs.
Claim 7
Independent Claim
113 words
A method of electronically converting the stator signals of a synchro to a digital equivalent indicative of the synchro rotor-to-stator angular position, said method comprising the steps of: a. demodulating the synchro stator signals; b. logically switching the demodulated signals to produce a first output pair indicative of a rotor-to-stator angular sector position, and a second output pair indicative of the sign and location of the sector; c. converting the first output pair of signals to a digital equivalent represenTative of the ratio of two stator voltages and; d. combining the second output signal pair with the converted first output pair to produce a digital signal indicative of the synchro rotor-to-stator angular position.
Claim 8
Independent Claim
113 words
A method of electronically converting the stator signals of a synchro to a digital equivalent indicative of the synchro rotor-to-stator angular position, said method comprising the steps of: a. demodulating the synchro stator signals; b. logically switching the demodulated signals to produce a first output pair indicative of a rotor-to-stator angular sector position, and a second output pair indicative of the sign and location of the sector; c. converting the first output pair of signals to a digital equivalent represenTative of the ratio of two stator voltages and; d. combining the second output signal pair with the converted first output pair to produce a digital signal indicative of the synchro rotor-to-stator angular position.
Claim 9
Dependent Claim
33 words
The method of claim 6 wherein demodulating of the stator signals is a sampling operation on the stator carrier peaks using the shifted rotor signal zero crossover as the stator signal peak reference.
Claim 10
Dependent Claim
59 words
The method of claim 6 wherein the combining of the signals is accomplished in a digital processor having a memory store of resultant calculations of angular rotor-to-stator position which is addressed by the converted first output signal, and an adder/subtracter to algebraically combine the memory store output and the second signal pair containing the sector location and sign information.
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) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |