US3670693A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Quartz crystal resonator tuning control apparatus
Assignee: Collins Radio Co
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Filing: 1971-03-23
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Granted: 1972-06-20
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Expires: 1991-03-23
Abstract
Abstract A quartz crystal resonator tuning plating automatic control process utilizing an automatic feedback control circuit in a process loop with the quartz crystal being metal plating tuned in an oscillator circuit. The frequency of the oscillator circuit is mixed with a reference frequency and the difference frequency is converted to dc applied to an RC circuit connected to a power amplifier for developing an exponential power output response from the power amplifier that melts and vaporizes plating metal (such as gold) in a vacuum chamber. This results in the plating rate on the quartz crystal being tuned processed tapering off from a much higher rate to a very low plating rate as the desired tuned frequency is approached. Minimum power level and shutoff controls are provided for the power amplifier in attaining desired levels of product frequency adjustment and plating cutoff.
Inventors
- 👤 William G Rorick
- 👤 Herbert O Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:49
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/22; C23C14/54; C23C14/542; C23C14/545; C23C14/546
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
241 words
In a metal plating tuning control process, apparatus for metal plating tuning of quartz crystals including: a quartz crystal metal plating chamber; an oscillator circuit with terminals for receiving a quartz crystal to be metal plate tune processed within said chamber; a reference frequency source; circuit means connected to receive frequency inputs from both said reference frequency source and said oscillator circuit and developing a dc output from the difference between the frequencies of said reference frequency source and the oscillator circuit; a power amplifier with dc input means developing a power output dependent on dc level input; RC time constant circuit means connected to receive said dc output and connected to said dc input means of said power amplifier; a plating metal supply in said chamber; metal melting and vaporizing heating means in said chamber for said plating metal supply; circuit means connecting the power output of said power amplifier to said heating means whereby tune plating of a crystal being plating tune processed is an exponential function tapering off from a high plating rate to a low plating rate as the desired crystal tuned frequency is approached a voltage comparator connected to a first dc voltage reference source and to said dc output as input connections; said voltage comparator having an output connection to a shutoff input of said power amplifier; and a second dc voltage reference source connected as a final rate reference input to said power amplifier.
Claim 2
Dependent Claim
241 words
In a metal plating tuning control process, apparatus for metal plating tuning of quartz crystals including: a quartz crystal metal plating chamber; an oscillator circuit with terminals for receiving a quartz crystal to be metal plate tune processed within said chamber; a reference frequency source; circuit means connected to receive frequency inputs from both said reference frequency source and said oscillator circuit and developing a dc output from the difference between the frequencies of said reference frequency source and the oscillator circuit; a power amplifier with dc input means developing a power output dependent on dc level input; RC time constant circuit means connected to receive said dc output and connected to said dc input means of said power amplifier; a plating metal supply in said chamber; metal melting and vaporizing heating means in said chamber for said plating metal supply; circuit means connecting the power output of said power amplifier to said heating means whereby tune plating of a crystal being plating tune processed is an exponential function tapering off from a high plating rate to a low plating rate as the desired crystal tuned frequency is approached a voltage comparator connected to a first dc voltage reference source and to said dc output as input connections; said voltage comparator having an output connection to a shutoff input of said power amplifier; and a second dc voltage reference source connected as a final rate reference input to said power amplifier.
Claim 3
Dependent Claim
53 words
In apparatus for the metal plating tuning of quartz crystals of claim 1, wherein said RC time constant circuit means includes parallel connected capacitive means and resistive means; and a resistor connected between the junction of said RC time constant circuit means and the dc input means of said power amplifIer and ground.
Claim 4
Dependent Claim
47 words
In apparatus for the metal plating tuning of quartz crystals of claim 1, wherein at least one of said first and second dc voltage reference sources is in the form of an adjustable tapped voltage divider connected between a voltage supply and a voltage potential reference source.
Claim 5
Dependent Claim
20 words
In apparatus for the metal plating tuning of quartz crystals of claim 3, wherein said chamber is a vacuum chamber.
Claim 6
Dependent Claim
27 words
In apparatus for the metal plating tuning of quartz crystals of claim 4, wherein said heating means is heating filament wire; and said plating metal is gold.
Claim 7
Dependent Claim
42 words
In apparatus for the metal plating tuning of quartz crystals of claim 5 adjustment means controlling the plating rate from an initial rate in the hundreds of parts per million per second to approximately 1 part per million per second at shutoff.
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) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |