US3679986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-linear feedback gain control and peak detector system
Assignee: International Business Machines Corp
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Filing: 1970-09-04
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Granted: 1972-07-25
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Expires: 1990-09-04
Abstract
Abstract A non-linear feedback gain control and peak detector system in which the output of an amplifier is compared with a reference voltage, and the error or difference therebetween is stored in a hold circuit which in turn controls the gain of the amplifier. Peak detection is accomplished by providing an output from the feedback control circuit, which provides a signal when the first voltage peak reaches its maximum value.
Inventors
- 👤 Louis F Zaman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:11
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3005; H03G3/301; H03G3/3015
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
201 words
An automatic gain control system comprising, in combination a variable gain amplifier having an input, an output, and a control circuit and arranged to vary the amplification of a signal supplied to the input in accordance with the variation of a control signal supplied to said control circuit, a control signal storage device, first current source means connected to said storage device for supplying energy at a predetermined rate to said control signal storage device, said first current source means being connected to the output of said amplifier and rendered effective at the beginning of an input signal to said variable gain amplifier to supply energy to said storage device, second current source means connected to said storage device for removing energy at a predetermined rate from said control signal storage device, said second current source means being governed by said first current source and rendered effective at the end of a predetermined time interval following the beginning of said input signal to said variable gain amplifier, and peak detector means connected to said first current source means, comprising means for detecting the termination of energy supply to said storage device and providing a peak detector output signal upon said termination.
Claim 2
Dependent Claim
201 words
An automatic gain control system comprising, in combination a variable gain amplifier having an input, an output, and a control circuit and arranged to vary the amplification of a signal supplied to the input in accordance with the variation of a control signal supplied to said control circuit, a control signal storage device, first current source means connected to said storage device for supplying energy at a predetermined rate to said control signal storage device, said first current source means being connected to the output of said amplifier and rendered effective at the beginning of an input signal to said variable gain amplifier to supply energy to said storage device, second current source means connected to said storage device for removing energy at a predetermined rate from said control signal storage device, said second current source means being governed by said first current source and rendered effective at the end of a predetermined time interval following the beginning of said input signal to said variable gain amplifier, and peak detector means connected to said first current source means, comprising means for detecting the termination of energy supply to said storage device and providing a peak detector output signal upon said termination.
Claim 3
Dependent Claim
33 words
An automatic gain control system as claimed in claim 1, in which said control signal storage device comprises a capacitor which is charged by said first source and discharged by said second source.
Claim 4
Dependent Claim
85 words
An automatic gain control system as claimed in claim 2, in which said first and second current sources comprise differentially connected stages having two inputs, one of which is connected to a reference potEntial and the other of which is connected to receive an input signal, the first current source connected to and receiving a control signal from the output of said variable gain amplifier, and the second current source connected to and receiving a control signal from the output of said first current source.
Claim 5
Dependent Claim
84 words
An automatic gain control system as claimed in claim 3, in which each of said current sources further includes a gating circuit for rendering said source effective, the gating circuit for said first source governed by the input to said amplifier and rendering said first source effective at the beginning of the input waveform to the system, and the gating circuit for the second source governed by the input to the amplifier rendering said second source effective following the completion of the input waveform.
Claim 6
Dependent Claim
40 words
An automatic gain control system as claimed in claim 4, in which the peak detector means includes resistance capacitance circuit delay means for rendering the peak detector means immune to short time variations in the charging current to said capacitor.
Claim 7
Dependent Claim
182 words
In an automatic gain control system, in combination, an operational amplifier having an input to which incoming signal waveforms are supplied, and an output from which output signal waveforms are supplied, said operational amplifier further including a feedback impedance connected between said input and said output, controllable impedance means connected in parallel with said feedback impedance, and having a control terminal to which gain control signals are supplied to thereby vary the impedance of said controllable impedance of said controllable impedance means, a gain control capacitor connected to said controllable impedance means, a first current source connected to said capacitor for supplying charging current to said control capacitor, said first current source being connected to and responsive to the output of said operational amplifier, a second current source connected to said capacitor for discharging said control capacitor, said second current source being connected to and responsive to the output of said first current source, and control means connected to said first and said second current sources for governing their operation in coordinated time relationship to the signal waveforms supplied to the system.
Claim 8
Dependent Claim
182 words
In an automatic gain control system, in combination, an operational amplifier having an input to which incoming signal waveforms are supplied, and an output from which output signal waveforms are supplied, said operational amplifier further including a feedback impedance connected between said input and said output, controllable impedance means connected in parallel with said feedback impedance, and having a control terminal to which gain control signals are supplied to thereby vary the impedance of said controllable impedance of said controllable impedance means, a gain control capacitor connected to said controllable impedance means, a first current source connected to said capacitor for supplying charging current to said control capacitor, said first current source being connected to and responsive to the output of said operational amplifier, a second current source connected to said capacitor for discharging said control capacitor, said second current source being connected to and responsive to the output of said first current source, and control means connected to said first and said second current sources for governing their operation in coordinated time relationship to the signal waveforms supplied to the system.
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |