US3935541A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Locked oscillator with damped oscillatory feedback
Assignee: Siemens AG
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Filing: 1974-07-16
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Granted: 1976-01-27
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Expires: 1994-07-16
Abstract
Abstract A circuit for locking an otherwise unstable oscillator to a frequency standard oscillation by the use of a discriminator and a differential amplifier, which amplifier produces a low-frequency output signal in response to a lack of synchronization between the oscillator being controlled and the reference oscillator.
Inventors
- 👤 Wilhelm Amend
- 👤 Toma Sotirovic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:07
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/10; H03L7/12
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
144 words
The combination comprising: a reference oscillator, a controlled oscillator having a control input to adjust its oscillation frequency, a discriminator having inputs received from both said oscillators for comparing the frequencies of each and producing a desired output indicative of the difference frequency therebetween, an amplifier receiving as its input, the output of said discriminator, and having its output coupled to the control input of the controlled oscillator, said amplifier having an ac feedback coupling circuit with its parameters chosen to cause said amplifier to carry out a damped oscillation after receiving a signal from the output of said discriminator, indicating non-synchronization between said oscillators, wherein said amplifier has first and second stages and is a difference amplifier and wherein the feedback circuit comprises an ac coupling means from the output electrode of the second stage to the input electrode of the first stage.
Claim 2
Dependent Claim
144 words
The combination comprising: a reference oscillator, a controlled oscillator having a control input to adjust its oscillation frequency, a discriminator having inputs received from both said oscillators for comparing the frequencies of each and producing a desired output indicative of the difference frequency therebetween, an amplifier receiving as its input, the output of said discriminator, and having its output coupled to the control input of the controlled oscillator, said amplifier having an ac feedback coupling circuit with its parameters chosen to cause said amplifier to carry out a damped oscillation after receiving a signal from the output of said discriminator, indicating non-synchronization between said oscillators, wherein said amplifier has first and second stages and is a difference amplifier and wherein the feedback circuit comprises an ac coupling means from the output electrode of the second stage to the input electrode of the first stage.
Claim 3
Dependent Claim
97 words
The combination in accordance with claim 1 wherein said difference amplifier is a two-stage transistor amplifier connected with common emitters, collector resistances being provided for said two-stage transistor amplifier, emitter resistances also provided in series with the emitters of said two-stage transistor amplifier, the collector resistances when compared to the emitter resistances being relatively higher, the control input of the controlled oscillator is coupled from the collector electrode of the first transistor stage, the ac coupling means for feedback is connected from the collector electrode of the second stage to the base electrode of the first stage.
References Cited (Backward Citations)
US2972720A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-26 | 1979-07-28 | 1980-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-26 | 1983-07-28 | 1984-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-26 | 1987-07-28 | 1988-01-27 | $7700.00 | Window Closed / Lapsed |