Patent US3852681A successfully refreshed from Google Patents.
US3852681A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable frequency oscillator systems
Assignee: US Philips Corp
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Filing: 1972-09-28
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Granted: 1974-12-03
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Expires: 1992-09-28
Abstract
Abstract The output of an oscillator is fed into a delay line and the phase difference across the delay line is compared in a comparator which gives a d.c. signal. This d.c. signal is fed back to control the oscillator. The oscillator will normally sit at one of a number of locking frequencies spaced apart so that the delay line gives a zero phase difference but by applying a compensating d.c. signal the oscillator can be set to any intermediate frequency. A square wave pulse is used to cause the oscillator to jump in frequency to the next locking frequency.
Inventors
- 👤 M Underhill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:05
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
109 words
A circuit comprising a variable frequency oscillator having a frequency control input and an output; a phase detector having a first input means for receiving a signal in accordance with said oscillator output, a second input, and an output coupled to said frequency control input; a series circuit having an input coupled to said oscillator output and an output coupled to said detector second input, said series circuit comprising a frequency converter having a plurality of output means for providing output signals of different phases, switching means coupled to said converter outputs for selecting one of said output signals and a means for delaying signals coupled to said converter.
Claim 2
Dependent Claim
109 words
A circuit comprising a variable frequency oscillator having a frequency control input and an output; a phase detector having a first input means for receiving a signal in accordance with said oscillator output, a second input, and an output coupled to said frequency control input; a series circuit having an input coupled to said oscillator output and an output coupled to said detector second input, said series circuit comprising a frequency converter having a plurality of output means for providing output signals of different phases, switching means coupled to said converter outputs for selecting one of said output signals and a means for delaying signals coupled to said converter.
Claim 3
Dependent Claim
41 words
A circuit as claimed in claim 1 wherein said converter is directly coupled to said oscillator output, a given one of said converter outputs is coupled to said detector first input, said switching means being coupled to said detector second input.
Claim 4
Dependent Claim
36 words
A circuit as claimed in claim 1 wherein said delaying means is directly coupled to said oscillator output, and further comprising a second frequency converter circuit coupled between said oscillator output and said detector first input.
Claim 5
Dependent Claim
56 words
A circuit as claimed in claim 1 wherein said converter comprises two serial coupled shift registers the output of the second register being coupled to the input of the first register, each of said registers comprising clock pulse inputs which comprise an input means for said conveter, and outputs which comprise output means for said converter.
Claim 6
Dependent Claim
14 words
A circuit as claimed in claim 1 wherein said converter comprises a frequency divider.
Claim 7
Dependent Claim
14 words
A circuit as claimed in claim 1 wherein said converter comprises a frequency multiplier.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |