Patent US4347407A successfully refreshed from Google Patents.
US4347407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic telephone circuit
Assignee: Nortel Networks Ltd
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Filing: 1980-08-27
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Granted: 1982-08-31
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Expires: 2000-08-27
Abstract
Abstract A telephone instrument circuit including electronic components for functions such as amplifying incoming and outgoing speech signals. When the electronic transducers of each electronic instruments have to operate in parallel with a carbon microphone in another instrument, problems are likely to arise. To deal with the problem, a voltage regulator is used which includes two essentially series coupled comparator-amplifiers, the first of which is driven by the circuit's supply voltage. The second amplifier has its own reference voltage and its output varies the reference voltage V R for the first amplifier, whose output is connected to the line whose voltage is being regulated. Above a preset line current, the I-V characteristic of the circuit is almost flat while below the preset threshold it is fairly steep to enable satisfactory parallel operation.
Inventors
- 👤 Peter F. Blomley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:04
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/738; H04M1/76; H04M1/60; H04M1/6025
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
209 words
A shunt voltage regulation circuit for a network external to said circuit, said network adapted for the bidirectional transfer of audio frequency signals, said circuit including a first and a second series coupled comparator amplifiers with both amplifiers having two inputs and at least one output, said first amplifier having a first input coupled to a supply of voltage to said network and a second input coupled to a source of reference voltage whereby an output of said first amplifier is a voltage dependent on the comparison of voltages at said inputs; said output from said first amplifier coupled to said network to supply regulated voltage thereto, a second output of said first amplifier coupled over a path to a first input of said second amplifier to apply a voltage proportional to the output of said first amplifier to said first input to said second amplifier, a second source of reference voltage coupled to the second input of said second amplifier, the output of said second amplifier coupled to the first source of reference voltage to adjust the first reference voltage in accordance with the value of the voltage of the output of said second amplifier representing a comparison between the voltges at the inputs to said second amplifier.
Claim 2
Dependent Claim
209 words
A shunt voltage regulation circuit for a network external to said circuit, said network adapted for the bidirectional transfer of audio frequency signals, said circuit including a first and a second series coupled comparator amplifiers with both amplifiers having two inputs and at least one output, said first amplifier having a first input coupled to a supply of voltage to said network and a second input coupled to a source of reference voltage whereby an output of said first amplifier is a voltage dependent on the comparison of voltages at said inputs; said output from said first amplifier coupled to said network to supply regulated voltage thereto, a second output of said first amplifier coupled over a path to a first input of said second amplifier to apply a voltage proportional to the output of said first amplifier to said first input to said second amplifier, a second source of reference voltage coupled to the second input of said second amplifier, the output of said second amplifier coupled to the first source of reference voltage to adjust the first reference voltage in accordance with the value of the voltage of the output of said second amplifier representing a comparison between the voltges at the inputs to said second amplifier.
Claim 3
Dependent Claim
64 words
A circuit as claimed in claim 1, in which the path from the second output of the first amplifier to the first input of the second amplifier includes a resistive impedance with a capacitor connected from that first input of the second amplifier to a source of ground voltage so that audio frequency signals from said network may be passed via the first amplifier.
Claim 4
Dependent Claim
30 words
A circuit as claimed in claim 1, in which there is a feedback connection from the regulated output of the first amplifier to the first input of the first amplifier.
Claim 5
Dependent Claim
35 words
A circuit as claimed in claim 1 in which said circuit is fabricated using bipolar integrated circuit techniques and wherein said first reference voltage is derived using available band gap reference of the integrated circuit.
Claim 6
Dependent Claim
116 words
A circuit for regulating the voltage in a telephone instrument powered from a two wire line, comprising a source of voltage derived from said line, a first source of reference voltage, a first comparator for comparing the voltages from said sources to produce an output from said comparator in response to a difference between the voltages from said sources, a path for channeling a voltage proportional to said voltage difference to an input of a second comparator, a second input of said second comparator coupled to receive a second reference voltage, said second comparator comparing the voltages at its inputs to produce an output for varying the voltage of said first source of reference voltage accordingly.
Claim 7
Dependent Claim
116 words
A circuit for regulating the voltage in a telephone instrument powered from a two wire line, comprising a source of voltage derived from said line, a first source of reference voltage, a first comparator for comparing the voltages from said sources to produce an output from said comparator in response to a difference between the voltages from said sources, a path for channeling a voltage proportional to said voltage difference to an input of a second comparator, a second input of said second comparator coupled to receive a second reference voltage, said second comparator comparing the voltages at its inputs to produce an output for varying the voltage of said first source of reference voltage accordingly.
Claim 8
Dependent Claim
42 words
A circuit for regulating voltage as claimed in claim 5, in which there is a feedback path from the output of said first comparator, said output being coupled to the source of line voltage, to said first input to said first comparator.
Claim 9
Dependent Claim
36 words
A circuit as claimed in claim 6, in which the circuit is configured in bipolar integrated circuit form and said first source of reference voltage is derived from band gap voltage available in said integrated circuit.
References Cited (Backward Citations)
US3973082A
Cited
US3989902A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-08-30 | 1986-03-01 | 1986-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-30 | 1990-03-01 | 1990-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-30 | 1994-03-01 | 1994-08-31 | $7700.00 | Window Closed / Lapsed |