US3906162A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loop extender with bypass capacitor discharge
Assignee: CMC TELECOM Corp
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Filing: 1974-07-30
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Granted: 1975-09-16
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Expires: 1994-07-30
Abstract
Abstract A telephone loop extending circuit for aiding central office battery. Each voltage insertion circuit includes the following: First and second pairs of terminals, first and second voltage sources, first and second transistors having base electrodes and emitter-collector electrode circuits. First sides of the first and second voltage sources, of opposite voltage polarity, are coupled to a first terminal of the corresponding pair. One side of the emitter-collector electrode circuit of each of the transistors is coupled to a second terminal of the corresponding pair. The other sides of the emitter-collector electrode circuits of the first and second transistors are individually coupled to second sides of, respectively, the first and second voltage sources. First and second optical coupling means are provided for the first and second transistors, respectively, each for sensing current flow between terminals of a pair and each being responsive to current flow in one of two opposite directions between terminals for enabling the corresponding transistor to couple the corresponding voltage source to the second terminal of the corresponding pair. A bypass capacitor is coupled from one terminal to the other of the corresponding pair for passing selected signals around the transistors and voltage sources from terminal to terminal. A resistor is coupled from the base electrodes of both transistors to the first sides of the voltage sources and is operative in combination with at least one of the transistors for providing a discharge path for the bypass capacitor after an externally applied signal is removed from terminals of the corresponding pair.
Inventors
- 👤 Frederic R Sparrevohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:30
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/001; H04M19/006
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
335 words
A telephone loop extending circuit for aiding central office battery and having first and second voltage insertion circuits, each voltage insertion circuit comprising: a pair of terminals, a circuit path for current flow coupled between terminals of the corresponding pair of terminals and comprising first and second voltage source means, first and second transistors each having base, emitter, and collector electrodes, first sides of said first and second voltage source means, of opposite voltage polarity, being coupled in the circuit path to a first terminal of the corresponding terminal pair, the emitter-collector electrode circuits of said first and second transistors being coupled in the circuit path from a second terminal of the corresponding pair to second sides of, respectively, said first and second voltage source means, optical coupling means corresponding to each said transistor and comprising a light responsive control means coupled to the base electrode of the corresponding transistor for controlling current flow therein and light emitting sensing means coupled in series in the circuit path for sensing externally applied current flow between terminals of the corresponding terminal pair and for applying light to the corresponding light responsive control means, thereby causing the latter to switch the corresponding transistor into saturated conduction coupling the corresponding voltage source means in series in the circuit path and in between terminals of the corresponding terminal pair, bypass capacitor means for bypassing selEcted signals around the portion of the circuit path formed by said transistors and voltage source means between two places along said circuit path, the improvement in each voltage insertion circuit comprising: impedance means coupled between the base electrodes of said first and second transistors and the first sides of said first and second voltage source means, and operative, in combination with at least one of said first and second transistors for providing a discharge path for the corresponding bypass capacitor means after removal of central office battery applied from a terminal in one voltage insertion circuit to a terminal in the other voltage insertion circuit.
Claim 2
Dependent Claim
335 words
A telephone loop extending circuit for aiding central office battery and having first and second voltage insertion circuits, each voltage insertion circuit comprising: a pair of terminals, a circuit path for current flow coupled between terminals of the corresponding pair of terminals and comprising first and second voltage source means, first and second transistors each having base, emitter, and collector electrodes, first sides of said first and second voltage source means, of opposite voltage polarity, being coupled in the circuit path to a first terminal of the corresponding terminal pair, the emitter-collector electrode circuits of said first and second transistors being coupled in the circuit path from a second terminal of the corresponding pair to second sides of, respectively, said first and second voltage source means, optical coupling means corresponding to each said transistor and comprising a light responsive control means coupled to the base electrode of the corresponding transistor for controlling current flow therein and light emitting sensing means coupled in series in the circuit path for sensing externally applied current flow between terminals of the corresponding terminal pair and for applying light to the corresponding light responsive control means, thereby causing the latter to switch the corresponding transistor into saturated conduction coupling the corresponding voltage source means in series in the circuit path and in between terminals of the corresponding terminal pair, bypass capacitor means for bypassing selEcted signals around the portion of the circuit path formed by said transistors and voltage source means between two places along said circuit path, the improvement in each voltage insertion circuit comprising: impedance means coupled between the base electrodes of said first and second transistors and the first sides of said first and second voltage source means, and operative, in combination with at least one of said first and second transistors for providing a discharge path for the corresponding bypass capacitor means after removal of central office battery applied from a terminal in one voltage insertion circuit to a terminal in the other voltage insertion circuit.
Claim 3
Dependent Claim
74 words
first and second transistors each having base, emitter, and collector electrodes, first sides of said first and second voltage sources, having opposite voltage polarity, being coupled, in the circuit path, to the first terminal of the corresponding terminal pair, the emitter-collector electrode circuits of said first and second transistors being coupled, in the circuit Path, from a second terminal of the corresponding pair to second sides of, respectively, said first and second voltage sources,
Claim 4
Dependent Claim
74 words
first and second transistors each having base, emitter, and collector electrodes, first sides of said first and second voltage sources, having opposite voltage polarity, being coupled, in the circuit path, to the first terminal of the corresponding terminal pair, the emitter-collector electrode circuits of said first and second transistors being coupled, in the circuit Path, from a second terminal of the corresponding pair to second sides of, respectively, said first and second voltage sources,
Claim 5
Dependent Claim
60 words
A telephone loop extending circuit according to claim 1 wherein said light emitting sensing means comprises unilateral current conductive means, the unilateral conductive means of each insertion circuit being coupled together in parallel circuit relation in opposite directions of current flow and in series circuit relation with the current flow through the circuit path between terminals of the corresponding pair.
Claim 6
Dependent Claim
115 words
A telephone loop extending circuit according to claim 2 wherein the parallel coupled unilateral conductive means are coupled in the corresponding circuit path in between the voltage source means and one terminal of the corresponding terminal pair and wherein said bypass capacitor means comprises first bypass capacitor means coupled from a first position in the corresponding circuit path in between the unilateral conductive means and the voltage source means to a position in the corresponding circuit path on the other side of the transistors and voltage source means and second bypass capacitor means coupled from the first position to a further position in the circuit path on the other side of the unilateral conductive means.
Claim 7
Dependent Claim
106 words
optical coupling means for corresponding to each of said transistors and comprising a light responsive transistor having emitter and collector electrodes coupled between the base electrode and the emitter-collector electrode circuit of the corresponding transistor and a light emitting diode coupled in series in the circuit path for sensing externally applied current flow between terminals of the corresponding terminal pair and responsive to such applied current for applying light to the corresponding light responsive transistor thereby causing the latter to switch the corresponding transistor into saturated conduction coupling the corresponding voltage source in series in the circuit path and in between terminals of the corresponding pair,
Claim 8
Dependent Claim
106 words
optical coupling means for corresponding to each of said transistors and comprising a light responsive transistor having emitter and collector electrodes coupled between the base electrode and the emitter-collector electrode circuit of the corresponding transistor and a light emitting diode coupled in series in the circuit path for sensing externally applied current flow between terminals of the corresponding terminal pair and responsive to such applied current for applying light to the corresponding light responsive transistor thereby causing the latter to switch the corresponding transistor into saturated conduction coupling the corresponding voltage source in series in the circuit path and in between terminals of the corresponding pair,
Claim 9
Dependent Claim
29 words
bypass capacitor means for bypassing selected signals around the portion of the circuit path formed by said transistors and voltage sources between two places along said circuit path, and
Claim 10
Dependent Claim
29 words
bypass capacitor means for bypassing selected signals around the portion of the circuit path formed by said transistors and voltage sources between two places along said circuit path, and
Claim 11
Dependent Claim
151 words
A telephone loop extending circuit according to claim 1 wherein said first and second voltage source means comprise first and second serially connected capacitor means and first and second full wave rectifier circuits for applying signals across, respectively, the first and second capacitor means, the first side of each of the voltage source means being at the common side of the capacitor means and the second side of the first and second voltage source means being at the other side, respectively, of the first and second capacitor means and additionally comprising in each insertion circuit a light emitting means coupled in the respective circuit path for forming light responsive to current flow in either direction, and controllable power supply means comprising means responsive to said light from either insertion circuit for enabling the power supply to commence applying alternating current exitation signals across said rectifier circuits in both said insertion circuits.
Claim 12
Dependent Claim
46 words
A telephone loop extending circuit according to claim 4 wherein said light emitting means of each insertion circuit comprises unilateral current conductive means and a diode rectifier circuit for coupling current flowing in either direction along the circuit in one direction through the unilaterally conductive means.
Claim 13
Dependent Claim
74 words
impedance means coupled between the base electrodes of said first and second transistors and the first sides of said first and second voltage sources, and operative, in combination with at least one of said first and second transistors for providing a discharge path for the corresponding bypass capacitor means after removal of central office battery applied from a terminal in the first pair of terminals to a terminal in the second pair of terminals.
Claim 14
Dependent Claim
74 words
impedance means coupled between the base electrodes of said first and second transistors and the first sides of said first and second voltage sources, and operative, in combination with at least one of said first and second transistors for providing a discharge path for the corresponding bypass capacitor means after removal of central office battery applied from a terminal in the first pair of terminals to a terminal in the second pair of terminals.
Claim 15
Dependent Claim
61 words
A telephone loop extending circuit for aiding central office battery, comprising: a. first and second pairs of terminals; b. first and second voltage insertion circuits corresponding, respectively, to the first and second pairs of terminals, each voltage insertion circuit having a circuit path for current flow coupled, respectively, between terminals of the corresponding pair of terminals, each voltage insertion circuit comprising:
Claim 16
Dependent Claim
61 words
A telephone loop extending circuit for aiding central office battery, comprising: a. first and second pairs of terminals; b. first and second voltage insertion circuits corresponding, respectively, to the first and second pairs of terminals, each voltage insertion circuit having a circuit path for current flow coupled, respectively, between terminals of the corresponding pair of terminals, each voltage insertion circuit comprising:
Claim 17
Dependent Claim
291 words
A telephone loop extending circuit for aiding central office battery comprising: first and second voltage insertion circuits, each comprising a. a pair of terminals, b. first and second voltage source means, c. first and second transistors each having a base electrode and an emitter-collector electrode circuit, d. means for coupling first sides, of opposite voltage polarity, of said first and second voltage source means to a first terminal of the corresponding terminal pair, e. means for coupling one side of the emitter-collector electrode circuit of each of said first and second transistors to a second terminal of the corresponding terminal pair, f. means for coupling the other side of the emitter-collector electrode circuit of each of said first and second transistors to second sides of, respectively, said first and second voltage source means, g. first and second optical coupling means corresponding to said first and second transistors, respectively, each for sensing current flowing between terminals and, each being responsive to current flow in one of two opposite directions between terminals for enabling the corresponding transistor to couple the corresponding voltage source to the second terminal of the corresponding pair, h. bypass capacitor means coupled from one terminal to the other of the corresponding pair for passing selected signals around said transistors and voltage source means and i. impedance means coupled between the base electrodes of said first and second transistors and the first sides of said first and second voltage source means, and operative, in combination with at least one of said first and second transistors for providing a discharge path for the bypass capacitor means after removal of central office battery applied from a terminal in the first voltage insertion circuit to a terminal in the second voltage insertion circuit.
Claim 18
Dependent Claim
291 words
A telephone loop extending circuit for aiding central office battery comprising: first and second voltage insertion circuits, each comprising a. a pair of terminals, b. first and second voltage source means, c. first and second transistors each having a base electrode and an emitter-collector electrode circuit, d. means for coupling first sides, of opposite voltage polarity, of said first and second voltage source means to a first terminal of the corresponding terminal pair, e. means for coupling one side of the emitter-collector electrode circuit of each of said first and second transistors to a second terminal of the corresponding terminal pair, f. means for coupling the other side of the emitter-collector electrode circuit of each of said first and second transistors to second sides of, respectively, said first and second voltage source means, g. first and second optical coupling means corresponding to said first and second transistors, respectively, each for sensing current flowing between terminals and, each being responsive to current flow in one of two opposite directions between terminals for enabling the corresponding transistor to couple the corresponding voltage source to the second terminal of the corresponding pair, h. bypass capacitor means coupled from one terminal to the other of the corresponding pair for passing selected signals around said transistors and voltage source means and i. impedance means coupled between the base electrodes of said first and second transistors and the first sides of said first and second voltage source means, and operative, in combination with at least one of said first and second transistors for providing a discharge path for the bypass capacitor means after removal of central office battery applied from a terminal in the first voltage insertion circuit to a terminal in the second voltage insertion circuit.
References Cited (Backward Citations)
US3781480A
Cited
US3757052A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |