Patent US4575690A successfully refreshed from Google Patents.
US4575690A
Expired / Lapsed
US
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Acceleration insensitive oscillator
Assignee: United States Department of the Army
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Filing: 1985-03-25
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Granted: 1986-03-11
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Expires: 2005-03-25
Abstract
Abstract A crystal oscillator, including two crystals of unequal acceleration sensvity magnitude and mounted such that their respective acceleration sensitivity vectors are aligned in an anti-parallel relationship, further includes at least one electrical reactance, such as a variable capacitor, coupled to one of the crystals for providing cancellation of acceleration sensitivities. After the acceleration sensitivity vectors of the two crystals are aligned anti-parallel, the variable capacitor is adjusted until the net or resultant acceleration sensitivity vector of the pair of resonators is reduced to zero. A second electrical reactance, such as a variable capacitor, is utilized as a tuning capacitor for adjusting the oscillator's output frequency to the desired value, while maintaining the cancellation of acceleration sensitivities.
Inventors
- 👤 Fred L. Walls
- 👤 John R. Vig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:58
CPC Classifications
H; H03; H03L; H03L1/00; H03B; H03B5/00; H03B5/30; H03B5/32; H03B2200/00; H03B2200/0014; H03B2200/0018
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
135 words
A method of suppressing the effects of vibration acting on a crystal resonator which comprises the primary frequency determining element of a crystal controlled oscillator, comprising the steps of: determining the magnitude and direction of the acceleration sensitivity vector representing the maximum change in frequency per change in acceleration for a first crystal; determining the magnitude and direction of the acceleration sensitivity vector representing the maximum change in frequency per change in acceleration for a second crystal; positioning two of said first and second crystals such that the respective acceleration sensitivity vectors are anti-parallel; electrically coupling said two crystals as a composite crystal resonator to an electrical oscillator circuit; and coupling electrical reactance means to one of said crystals for cancelling any difference in the magnitudes of the acceleration sensitivity vectors of said two crystals.
Claim 2
Independent Claim
135 words
A method of suppressing the effects of vibration acting on a crystal resonator which comprises the primary frequency determining element of a crystal controlled oscillator, comprising the steps of: determining the magnitude and direction of the acceleration sensitivity vector representing the maximum change in frequency per change in acceleration for a first crystal; determining the magnitude and direction of the acceleration sensitivity vector representing the maximum change in frequency per change in acceleration for a second crystal; positioning two of said first and second crystals such that the respective acceleration sensitivity vectors are anti-parallel; electrically coupling said two crystals as a composite crystal resonator to an electrical oscillator circuit; and coupling electrical reactance means to one of said crystals for cancelling any difference in the magnitudes of the acceleration sensitivity vectors of said two crystals.
Claim 3
Dependent Claim
15 words
The method as defined by claim 1 wherein said reactance means comprises capacitive reactance means.
Claim 4
Dependent Claim
15 words
The method as defined by claim 1 wherein said reactance means comprises inductive reactance means.
Claim 5
Dependent Claim
38 words
The method as defined by claim 1 wherein said two crystals are electrically connected in series to said oscillator circuit and wherein said reactance means comprises variable capacitance means coupled in parallel across one of said two crystals.
Claim 6
Dependent Claim
28 words
The method as defined by claim 4 wherein said variable capacitance means is coupled across the crystal of said two crystals having the greater magnitude of acceleration sensitivity.
Claim 7
Dependent Claim
21 words
The method as defined by claim 1 wherein said first and second crystal are connected in parallel to said oscillator circuit.
Claim 8
Dependent Claim
21 words
The method as defined by claim 6 and wherein said reactance means is connected in series to one of said crystals.
Claim 9
Dependent Claim
15 words
The method as defined by claim 7 wherein said reactance means comprises capacitive reactance means.
Claim 10
Dependent Claim
15 words
The method as defined by claim 7 wherein said reactance means comprises inductive reactance means.
Claim 11
Dependent Claim
32 words
The method as defined by claim 7 wherein said reactance means comprises variable capacitance means connected in series to the crystal of said two crystals having the larger magnitude of acceleration sensitivity.
Claim 12
Dependent Claim
34 words
The method as defined by claim 1 and additionally including the step of coupling electrical reactance means between said composite resonator and said oscillator circuit for adjusting the output frequency of the oscillator circuit.
Claim 13
Dependent Claim
20 words
The method as defined by claim 11 wherein said reactance means of the last recited step comprises capacitive reactance means.
Claim 14
Dependent Claim
20 words
The method as defined by claim 11 wherein said reactance means of the last recited step comprises inductive reactance means.
Claim 15
Dependent Claim
28 words
The method as defined by claim 11 wherein said reactance means coupled between said composite resonator and said oscillator circuit comprises variable capacitance means coupled in series therebetween.
Claim 16
Independent Claim
127 words
The apparatus for suppressing the effects of vibration on a piezoelectric crystal resonator constituting the primary frequency determining element of a crystal controlled oscillator, comprising: an oscillator; a composite crystal resonator coupled to said oscillator and comprising first and second resonator crystals, each having an acceleration sensitivity vector of unequal magnitude, said crystals being further positioned such that the acceleration sensitivity vector of the first crystal is disposed in an anti-parallel relationship with the acceleration sensitivity vector of said second crystal whereby the effective acceleration in all directions on the resonant frequency of the composite crystal resonator is substantially reduced; and electrical reactance means coupled to at least one of said first and second resonator crystals for cancelling any net resultant acceleration sensitivity vector between said crystals.
Claim 17
Independent Claim
127 words
The apparatus for suppressing the effects of vibration on a piezoelectric crystal resonator constituting the primary frequency determining element of a crystal controlled oscillator, comprising: an oscillator; a composite crystal resonator coupled to said oscillator and comprising first and second resonator crystals, each having an acceleration sensitivity vector of unequal magnitude, said crystals being further positioned such that the acceleration sensitivity vector of the first crystal is disposed in an anti-parallel relationship with the acceleration sensitivity vector of said second crystal whereby the effective acceleration in all directions on the resonant frequency of the composite crystal resonator is substantially reduced; and electrical reactance means coupled to at least one of said first and second resonator crystals for cancelling any net resultant acceleration sensitivity vector between said crystals.
Claim 18
Dependent Claim
15 words
The apparatus as defined by claim 15 wherein said reactance means comprises capacitive reactance means.
Claim 19
Dependent Claim
15 words
The apparatus as defined by claim 15 wherein said reactance means comprises inductive reactance means.
Claim 20
Dependent Claim
39 words
The apparatus as defined by claim 15 wherein said first and second resonator crystals are connected in series to said oscillator and wherein said reactance means comprises variable capacitance means coupled in parallel across one of said resonator crystals.
Claim 21
Dependent Claim
25 words
The apparatus as defined by claim 18 wherein said variable capacitance means is coupled across the resonator crystal having the greater magnitude of acceleration sensitivity.
Claim 22
Dependent Claim
39 words
The apparatus as defined by claim 15 wherein said first and second resonator crystals are connected in parallel to said oscillator and wherein said reactance means comprises variable capacitance means coupled in series to one of said resonator crystals.
Claim 23
Dependent Claim
28 words
The apparatus as defined by claim 20 and wherein said variable capacitance means is coupled in series to the resonator crystal having the greater magnitude of acceleration sensitivity.
Claim 24
Dependent Claim
33 words
The apparatus as defined by claim 15 and additionally including electrical reactance means coupled between said composite resonator and said oscillator for adjusting the output frequency of said oscillator to a desired value.
Claim 25
Dependent Claim
27 words
The apparatus as defined by claim 22 wherein said last recited reactance means comprises capacitive reactance means coupled in series between said composite resonator and said oscillator.
Claim 26
Dependent Claim
27 words
The apparatus as defined by claim 22 wherein said last recited reactance means comprises inductive reactance means coupled in series between said composite resonator and said oscillator.
Claim 27
Dependent Claim
83 words
The apparatus as defined by claim 22 and wherein said first and second crystals additionally have different capacitance ratios and are connected in series, and wherein said first recited reactance means coupled to one of said resonator crystals comprises variable capacitance means coupled in parallel to said one crystal whereby the parallel connected variable capacitance means is used to produce substantially zero net acceleration sensitivity, and wherein said last recited reactance means comprises variable capacitance means used as an output frequency tuning capacitor.
Claim 28
Dependent Claim
82 words
The apparatus as defined by claim 22 wherein said first and second crystals additionally have different capacitance ratios and are connected in parallel and wherein said first recited reactance means coupled to one of said resonator crystals comprises variable capacitance means coupled in series to said one crystal, whereby the first recited series capacitor means is used to produce substantially zero net acceleration sensitivity and wherein said last recited reactance means comprises variable capacitance means used as an output frequency tuning capacitor.
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