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US4536721A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low noise crystal oscillator
Assignee: Adret Electronique SA
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Filing: 1984-04-09
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Granted: 1985-08-20
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Expires: 2004-04-09
Abstract
Abstract A crystal oscillator comprises an active coupling member driving the series mode resonance of a piezoelectric crystal proportionally to a feedback voltage. Said coupling member is followed by a current boosting transformer whose secondary winding is connected to an output amplifier and to a clipping amplifier shunted across said secondary winding and itself followed by a band-pass filter which supplies said feedback voltage to said coupling member.
Inventors
- 👤 Roger Charbonnier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:12
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/36; H03B2200/00; H03B2200/006; H03B2200/007; H03B2200/0088; H03B2200/009; H03B2202/00; H03B2202/01; H03B2202/012; H03B2202/015
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
96 words
An oscillator comprising: a crystal resonator; active coupling circuit means having first and second inputs and an output, the first input being connected to the crystal resonator; a current booster transformer having primary and secondary windings, the primary winding being connected to the output of the coupling circuit means; output amplifier means connected in series with the secondary winding; amplitude limiting amplifier means connected in parallel across the secondary winding said amplitude limiting amplifier means having an output; and band-pass filter means connecting the output of said amplitude limiting amplifier means to the said second input.
Claim 2
Dependent Claim
96 words
An oscillator comprising: a crystal resonator; active coupling circuit means having first and second inputs and an output, the first input being connected to the crystal resonator; a current booster transformer having primary and secondary windings, the primary winding being connected to the output of the coupling circuit means; output amplifier means connected in series with the secondary winding; amplitude limiting amplifier means connected in parallel across the secondary winding said amplitude limiting amplifier means having an output; and band-pass filter means connecting the output of said amplitude limiting amplifier means to the said second input.
Claim 3
Dependent Claim
15 words
An oscillator as claimed in claim 1, wherein the coupling circuit means include a transistor.
Claim 4
Dependent Claim
24 words
An oscillator as claimed in claim 2, wherein the amplitude limiting amplifier means include two transistors arranged in a differential circuit and alternately conductive.
Claim 5
Dependent Claim
16 words
An oscillator as claimed in claim 3, wherein the band-pass filter means comprises a Wien network.
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) | 1988-08-19 | 1989-02-18 | 1989-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-19 | 1993-02-18 | 1993-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-19 | 1997-02-18 | 1997-08-20 | $7700.00 | Window Closed / Lapsed |