Patent US4020426A successfully refreshed from Google Patents.
US4020426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature compensation circuit for crystal oscillator
Assignee: Compagnie Electronique et de Piezoelectricite CEPE
•
Filing: 1975-09-02
•
Granted: 1977-04-26
•
Expires: 1995-09-02
Abstract
Abstract A crystal-controlled oscillator whose frequency is regulated as a function of temperature and having a feedback loop with a capacitor whose capacitance is electrically variable, to which capacitor a variable electrical compensating signal varying in accordance with a third-degree law as a function of temperature, is applied. The compensating circuit in accordance with the invention produces a signal of this kind at its terminals by three units respectively comprising three thermistors R T1 , R T2 , R T3 , each unit being specifically designed to create the signal corresponding to a given arcuate portion of the total graph function. The applications are in particular in the field of portable radio transmitters.
Inventors
- 👤 Jacques Helle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:43
CPC Classifications
H; H03; H03L; H03L1/00; H03L1/02; H03L1/022; H03L1/023; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/36; H03H; H03H3/00; H03H3/007; H03H3/02; H03H3/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
200 words
A crystal-controlled oscillator whose frequency can be regulated within a wide range of temperatures and which comprises: an oscillating circuit in the form of a feedback loop, comprising an amplifier, a piezo-electric oscillator, and an element with a first pair of terminals, said element having a reactance which is variable as a function of an electrical signal applied to its terminals; and a compensating circuit with a second pair of terminals comprising temperature-sensitive elements, an electrical characteristic of which depends upon the temperature, said compensating circuit delivering at its terminals a compensating electrical signal, said first pair of terminals being connected to said second pair, wherein one of the terminals of the said second pair, in operation, is maintained at a fixed potential by a voltage divider, and the other is at an applied potential which is variable as a function of the temperature, and a first and second of said temperature-sensitive elements are connected by one of their ends to said other terminal, their other ends being respectively connected to two voltage dividers, of which one comprises a third one of said elements, the three dividers being adapted to be connected to the terminals of an electrical energy source.
Claim 2
Dependent Claim
200 words
A crystal-controlled oscillator whose frequency can be regulated within a wide range of temperatures and which comprises: an oscillating circuit in the form of a feedback loop, comprising an amplifier, a piezo-electric oscillator, and an element with a first pair of terminals, said element having a reactance which is variable as a function of an electrical signal applied to its terminals; and a compensating circuit with a second pair of terminals comprising temperature-sensitive elements, an electrical characteristic of which depends upon the temperature, said compensating circuit delivering at its terminals a compensating electrical signal, said first pair of terminals being connected to said second pair, wherein one of the terminals of the said second pair, in operation, is maintained at a fixed potential by a voltage divider, and the other is at an applied potential which is variable as a function of the temperature, and a first and second of said temperature-sensitive elements are connected by one of their ends to said other terminal, their other ends being respectively connected to two voltage dividers, of which one comprises a third one of said elements, the three dividers being adapted to be connected to the terminals of an electrical energy source.
Claim 3
Dependent Claim
60 words
A crystal-controlled oscillator as claimed in claim 1, wherein said temperature-sensitive elements provide to the said electrical compensating signal, within its range of variation as a function of increasing temperatures, first and third portions of rising values corresponding to the ends of said range, and a second portion produces the decreasing values corresponding to the intermediate part of said range.
Claim 4
Dependent Claim
25 words
A crystal-controlled oscillator as claimed in claim 1, wherein each of the three temperature-sensitive elements is respectively connected through a resistor shunted across its ends.
Claim 5
Dependent Claim
43 words
A crystal-controlled oscillator as claimed in claim 1, wherein each of the terminals of said first pair is connected to each of the terminals of said second pair through a resistor which has a high resistance compared with that of the voltage dividers.
Claim 6
Dependent Claim
36 words
A crystal-controlled oscillator as claimed in claim 1, wherein said temperature-sensitive elements have a resistance which decreases as a function of temperature, said third element being connected to the positive terminal of said electrical energy source.
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) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |