US3576498A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sweep frequency oscillator drift correction systems
Assignee: Eaton Corp
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Filing: 1969-10-15
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Granted: 1971-04-27
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Expires: 1989-10-15
Abstract
Abstract A system for stabilizing the frequency of a voltage-controlled sweep frequency oscillator driven from a sawtooth generator is disclosed. The oscillator drives a frequency discriminator centered at the desired minimum low frequency of the oscillator. During the flyback interval of the sawtooth generator, a singleshot multivibrator is triggered which, by switching, removes the generator sweep voltage and the center frequency voltage from the oscillator and substitutes therefor a predetermined zero set voltage which returns the oscillator frequency to the same minimum low frequency just before each sweep begins. The error voltage from the discriminator, sampled during this period, is applied to a low-leakage capacitor which continuously supplies an integrated correction signal to the oscillator. The multivibrator returns to its stable state at the beginning of each sweep period and switches the oscillator back to its normal sweep control by the sawtooth generator.
Inventors
- 👤 Julian D Hirsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:53
CPC Classifications
H; H03; H03B; H03B23/00; H03B2200/00; H03B2200/006; H03B2200/0092
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
157 words
A stabilized sweep frequency generator responsive to an applied input control signal comprising: a voltage-controlled oscillator for generating an output signal having a frequency which varies as a function of the magnitude of a control voltage applied to its input; a discriminator for developing an error signal proportional to the deviation of the frequency of an input signal from a fixed center frequency; means applying said output signal to the input of the discriminator; means for generating a periodic variable control signal; means for supplying a fixed reference control signal; means for periodically substituting the reference control signal for the periodic variable control signal as control input to the oscillator; means for sampling the error signal from the discriminator only during the time said reference control signal is applied to said oscillator; means for integrating said sampled error signal; and means presenting said integrated error signal as a correction signal to the control input of said oscillator.
Claim 2
Dependent Claim
157 words
A stabilized sweep frequency generator responsive to an applied input control signal comprising: a voltage-controlled oscillator for generating an output signal having a frequency which varies as a function of the magnitude of a control voltage applied to its input; a discriminator for developing an error signal proportional to the deviation of the frequency of an input signal from a fixed center frequency; means applying said output signal to the input of the discriminator; means for generating a periodic variable control signal; means for supplying a fixed reference control signal; means for periodically substituting the reference control signal for the periodic variable control signal as control input to the oscillator; means for sampling the error signal from the discriminator only during the time said reference control signal is applied to said oscillator; means for integrating said sampled error signal; and means presenting said integrated error signal as a correction signal to the control input of said oscillator.
Claim 3
Dependent Claim
159 words
A stabilized sweep frequency signal generating system for cyclically generating a sweep signal of a frequency proportional to the magnitude of an applied input signal comprising: a voltage-controlled oscillator responsive to an applied control signal for generating a variable frequency output signal; a frequency discriminator having a stable center frequency and an input connected to said variable frequency output signal to produce an output error signal; a sawtooth generator for generating a variable control signal; means for supplying a fixed reference control signal; switching means controlled by said sawtooth generator for periodically substituting said fixed control signal for said variable control signal as the control input to said oscillator; a storage capacitor; means for periodically charging said storage capacitor from said error signal only during the time when said fixed control signal is applied to said oscillator to develop a capacitor voltage; and means presenting said capacitor voltage as a correction signal to the control input of the oscillator.
Claim 4
Dependent Claim
159 words
A stabilized sweep frequency signal generating system for cyclically generating a sweep signal of a frequency proportional to the magnitude of an applied input signal comprising: a voltage-controlled oscillator responsive to an applied control signal for generating a variable frequency output signal; a frequency discriminator having a stable center frequency and an input connected to said variable frequency output signal to produce an output error signal; a sawtooth generator for generating a variable control signal; means for supplying a fixed reference control signal; switching means controlled by said sawtooth generator for periodically substituting said fixed control signal for said variable control signal as the control input to said oscillator; a storage capacitor; means for periodically charging said storage capacitor from said error signal only during the time when said fixed control signal is applied to said oscillator to develop a capacitor voltage; and means presenting said capacitor voltage as a correction signal to the control input of the oscillator.
Claim 5
Dependent Claim
178 words
A stabilized sweep frequency signal generating system for cyclically generating a sweep signal of a frequency proportional to the magnitude of an applied input signal comprising: a voltage-controlled oscillator responsive to an applied control voltage for generating a variable frequency output signal; a frequency discriminator having a stable center frequency and an input connected to said output signal to produce an output error signal; a sawtooth generator for generating a sawtooth control signal; means for supplying a reference control signal; a monostable multivibrator controlled by said sawtooth Generator to supply periodic switching signals during the flyback time of the sawtooth signal; switching means responsive to said switching signals for alternatively substituting said reference control signal for said sawtooth control signal as the input control signal to the oscillator; a storage capacitor; means for charging said capacitor from said error signal only during the time when said reference signal is applied to said oscillator to develop a capacitor voltage; and means coupling said capacitor voltage to the control input of said oscillator to supply an integrated correction signal thereto.
Claim 6
Dependent Claim
178 words
A stabilized sweep frequency signal generating system for cyclically generating a sweep signal of a frequency proportional to the magnitude of an applied input signal comprising: a voltage-controlled oscillator responsive to an applied control voltage for generating a variable frequency output signal; a frequency discriminator having a stable center frequency and an input connected to said output signal to produce an output error signal; a sawtooth generator for generating a sawtooth control signal; means for supplying a reference control signal; a monostable multivibrator controlled by said sawtooth Generator to supply periodic switching signals during the flyback time of the sawtooth signal; switching means responsive to said switching signals for alternatively substituting said reference control signal for said sawtooth control signal as the input control signal to the oscillator; a storage capacitor; means for charging said capacitor from said error signal only during the time when said reference signal is applied to said oscillator to develop a capacitor voltage; and means coupling said capacitor voltage to the control input of said oscillator to supply an integrated correction signal thereto.
Claim 7
Dependent Claim
41 words
A system in accordance with claim 3, wherein the means for charging said capacitor includes: a DC amplifier connected to the discriminator output; a dual-polarity limiter connected to the amplifier output; and a charging resistor for controlling the charging time constant.
Claim 8
Dependent Claim
34 words
A system in accordance with claim 3, wherein the means coupling said capacitor voltage to the control input of said oscillator includes: a field-effect transistor source-follower amplifier and a DC amplifier connected in cascade.
Claim 9
Dependent Claim
19 words
A system in accordance with claim 3, wherein the switching means includes: field-effect transistors connected in a switching mode.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |