US4224580A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Quartz crystal oscillator
Assignee: Alps Alpine Co Ltd
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Filing: 1978-11-06
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Granted: 1980-09-23
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Expires: 1998-11-06
Abstract
Abstract A Colpitts type quartz crystal oscillator comprises a resonant circuit consisting of two capacitors connected in series across a quartz crystal, the latter serving as an inductive element. The resonant circuit is connected between the base and collector of a transistor, with the junction of the capacitors being connected to the emitter of the transistor to provide feedback. Means are provided to increase the gain of the transistor and thereby the driving excitation of the crystal above a normal value for a brief length of time after the oscillator is initially energized.
Inventors
- 👤 Akiyuki Yoshisato
- 👤 Katsumi Tobita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:23
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/36; H03B5/362; H03L; H03L3/00; H03B2200/00; H03B2200/0002; H03B2200/0008; H03B2200/003; H03B2200/0052; H03B2200/006; H03B2200/0082; H03B2200/0094; H03B7/00; H03B7/02; H03B7/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
120 words
A crystal oscillator comprising: a resonant circuit including a crystal; an active element connected to said resonant circuit for applying a driving excitation to said resonant circuit; a first capacitor connected to said active element for stabilizing operation of said oscillator, said first capacitor having a relatively low impedance to signals in the frequency range of said oscillator; feedback means connected between said resonant circuit and said active element for applying a feedback signal from said resonant circuit to said active element; and initialization means including an electrolytic capacitor connected in parallel with said first capacitor for increasing the gain of said active element above a normal value for a predetermined length of time after initial energization of the oscillator.
Claim 2
Dependent Claim
120 words
A crystal oscillator comprising: a resonant circuit including a crystal; an active element connected to said resonant circuit for applying a driving excitation to said resonant circuit; a first capacitor connected to said active element for stabilizing operation of said oscillator, said first capacitor having a relatively low impedance to signals in the frequency range of said oscillator; feedback means connected between said resonant circuit and said active element for applying a feedback signal from said resonant circuit to said active element; and initialization means including an electrolytic capacitor connected in parallel with said first capacitor for increasing the gain of said active element above a normal value for a predetermined length of time after initial energization of the oscillator.
Claim 3
Dependent Claim
15 words
A crystal oscillator as in claim 1, in which the active element comprises a transistor.
Claim 4
Dependent Claim
22 words
A crystal oscillator as in claim 2, in which the resonant circuit, transistor and feedback means are connected in a Colpitts configuration.
Claim 5
Dependent Claim
53 words
A crystal oscillator as in claim 3, in which the resonant circuit comprises two capacitors connected in series between a base and a collector of the transistor, the crystal being connected between the base and collector of the transistor, a junction of said two capacitors being connected to an emitter of the transistor.
Claim 6
Dependent Claim
92 words
A crystal oscillator as in claim 1, said active element being constituted by a transistor, and said resonant circuit, said transistor and said feedback means are connected in a Colpitts configuration in which the resonant circuit comprises two capacitive elements connected in series between the base and the collector of said transistor, the crystal being connected between the base and collector of said transistor, and the junction of said two capacitive elements being connected to the emitter of said transistor, and said initialization capacitor being connected between said emitter and said junction.
Claim 7
Dependent Claim
24 words
A crystal oscillator as in claim 1, said initialization capacitor being an electrolytic capacitor having a capacitance larger than that of said first capacitor.
References Cited (Backward Citations)
US3559100A
Cited
SU510767A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-23 | 1984-03-24 | 1984-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-23 | 1988-03-24 | 1988-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-23 | 1992-03-24 | 1992-09-23 | $7700.00 | Window Closed / Lapsed |