US3728641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable temperature compensating capacitor for crystal oscillators
Assignee: Suwa Seikosha KK
•
Filing: 1971-08-03
•
Granted: 1973-04-17
•
Expires: 1991-08-03
Abstract
Abstract A temperature sensitive capacitor having a dielectric such as BaTiO3, wherein capacitance varies in response to temperature, is provided with means for manually changing the capacitance thereof either in a stepwise manner or continuously.
Inventors
- 👤 K Fujita
- 👤 H Mitsui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:26
CPC Classifications
H; H03; H03L; H03L1/00; H03L1/02; H03L1/028; G; G04; G04F; G04F5/00; G04F5/04; G04F5/06; G04F5/063; G04F5/066; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/36; H03B5/364
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
121 words
In a crystal oscillator having a crystal vibrator and wherein the oscillating frequency varies in accordance with temperature, the improvement which comprises a single manually variable temperature compensating ferroelectric condenser having a pair of output terminals; a temperature compensating ferroelectric dielectric; a fixed electrode plate mounted on one side of said dielectric and coupled to one of said output terminals; and manually adjustable means including electrode means mounted on the other side of said dielectric in facing relation to said fixed plate and coupled to the other of said output terminals for manually varying the capacitance of said condenser by manually selecting the area of said dielectric between said fixed plate and electrode means in the circuit between said output terminals.
Claim 2
Dependent Claim
121 words
In a crystal oscillator having a crystal vibrator and wherein the oscillating frequency varies in accordance with temperature, the improvement which comprises a single manually variable temperature compensating ferroelectric condenser having a pair of output terminals; a temperature compensating ferroelectric dielectric; a fixed electrode plate mounted on one side of said dielectric and coupled to one of said output terminals; and manually adjustable means including electrode means mounted on the other side of said dielectric in facing relation to said fixed plate and coupled to the other of said output terminals for manually varying the capacitance of said condenser by manually selecting the area of said dielectric between said fixed plate and electrode means in the circuit between said output terminals.
Claim 3
Dependent Claim
55 words
A crystal oscillator as recited in claim 1, wherein said manually adjustable means includes a displaceable plate defining said electrode means mounted on said other side of said dielectric, and means for manually displacing said displaceable plate for varying the overlapping areas between said fixed and displaceable plates, and therefor the capacitance of said condenser.
Claim 4
Dependent Claim
25 words
A crystal oscillator as recited in claim 11, wherein said means for manually displacing said displaceable plate includes a rotor pivotably mounted on said dielectric.
Claim 5
Dependent Claim
57 words
A crystal oscillator as recited in claim 1, wherein said manually adjustable means includes a segmented plate fixed to said other side of said dielectric and defining said electrode means and displaceable contact means for selectively engaging one or more of said plate segments to electrically connect said plate segments to the other of said output terminals.
Claim 6
Dependent Claim
34 words
A crystal oscillator as recited in claim 4, wherein the segments defining said segmented electrode are each of a different area, said displaceable contact means being selectively engageable against any one of said segments.
Claim 7
Dependent Claim
44 words
A crystal oscillator as recited in claim 4, wherein said segmented plate includes a plurality of segments, said displaceable electrode being positioned for selectively and sequentially electrically connecting respective segments of said segmented plate together for a step-wise adjustment of capacitance of said condenser.
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) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |