Patent US3743945A successfully refreshed from Google Patents.
US3743945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Limiter for multi frequency voice receiver
Assignee: U S Holding Co Inc
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Filing: 1970-12-23
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Granted: 1973-07-03
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Expires: 1990-12-23
Abstract
Abstract A multi-frequency receiver for use in telecommunications system receives tones within the audio frequency range. The tones transmitted to the receiver must be selectively separated, amplified, shaped, selectively separated once again into individual frequency bands and validated, through individual stages of the receiver. In each stage, a series of tests are applied to the tones before digital signals are transmitted responsive to the tone. The pulse shaping or limiting, associated with amplification and the tone signal check undertaken in that stage within the framework set out herein, is disclosed.
Inventors
- 👤 D Sellari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:48
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/126; H03K; H03K5/00; H03K5/01; H03K5/08; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H04Q1/444; H04Q1/45; H04Q1/453
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
177 words
An apparatus for producing essentially square wave signal output from essentially sinusoidal signal input comprising: a pair of voltage sensing members connected to receive an alternating current wave signal in multiple from said input network, means for opposedly biasing said sensing members, means for feeding reference voltages to said sensing members for comparison with the input signals to trigger each of said sensing members on alternate polarity portions of a signal wave, gating means individually connected to each member to receive the output of the sensing member to which connected, a first of said gating means responsive to the initiation of output from a first of said sensing members to initiate a square wave signal, a second of said gating means responsive to the initiation of the output from the other of said sensing members for terminating said square wave, an output path for said square wave signal, said path being common to both said gating means, and a feedback path from said common output path to one of said sensing members to impose a delay thereon.
Claim 2
Independent Claim
177 words
An apparatus for producing essentially square wave signal output from essentially sinusoidal signal input comprising: a pair of voltage sensing members connected to receive an alternating current wave signal in multiple from said input network, means for opposedly biasing said sensing members, means for feeding reference voltages to said sensing members for comparison with the input signals to trigger each of said sensing members on alternate polarity portions of a signal wave, gating means individually connected to each member to receive the output of the sensing member to which connected, a first of said gating means responsive to the initiation of output from a first of said sensing members to initiate a square wave signal, a second of said gating means responsive to the initiation of the output from the other of said sensing members for terminating said square wave, an output path for said square wave signal, said path being common to both said gating means, and a feedback path from said common output path to one of said sensing members to impose a delay thereon.
Claim 3
Dependent Claim
53 words
An apparatus as claimed in claim 1, wherein each said gating means comprises a separate NAND gate connected to receive the output of an individual sensing member, and a latching output of each of said gating means connected to the input of the other gating means to retain said wave signal once initiated.
Claim 4
Independent Claim
203 words
An apparatus for producing essentially square wave signal output from essentially sinusoidal signal input comprising: a pair of voltage sensing members connected to receive an alternating current wave signal in multiple from said input network, means for opposedly biasing said sensing members, means for feeding reference voltages to said sensing members for comparison with the input signals to trigger each of said sensing members on alternate polarity portions of a signal wave, individual gating means connected to each member to receive the output of each of said sensing members, a first of said gating means responsive to the initiation of output from a first of said sensing members to initiate a square wave signal, and said other gating means responsive to the initiation of the output from the other of said sensing members for terminating said square wave of said signal, wherein each said sensing member comprises an operational amplifier and wherein there is output means responsive to the output of the first of said amplifiers to initiate said square wave output and a feedback path from the output of the gating means connected to said first member to the signal input of said first amplifier to provide a delay in said input.
Claim 5
Independent Claim
203 words
An apparatus for producing essentially square wave signal output from essentially sinusoidal signal input comprising: a pair of voltage sensing members connected to receive an alternating current wave signal in multiple from said input network, means for opposedly biasing said sensing members, means for feeding reference voltages to said sensing members for comparison with the input signals to trigger each of said sensing members on alternate polarity portions of a signal wave, individual gating means connected to each member to receive the output of each of said sensing members, a first of said gating means responsive to the initiation of output from a first of said sensing members to initiate a square wave signal, and said other gating means responsive to the initiation of the output from the other of said sensing members for terminating said square wave of said signal, wherein each said sensing member comprises an operational amplifier and wherein there is output means responsive to the output of the first of said amplifiers to initiate said square wave output and a feedback path from the output of the gating means connected to said first member to the signal input of said first amplifier to provide a delay in said input.
Claim 6
Dependent Claim
49 words
An apparatus as claimed in claim 3, wherein there is a direct current source, a voltage divider across said source and said reference voltage feeding means is connected to said divider across a resistance therein to offset the voltages fed to one amplifier from those fed to the other.
Claim 7
Dependent Claim
22 words
An apparatus as claimed in claim 3, wherein said amplifiers are high gain devices to approximate switching response to the signal input.
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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |