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US3883696A
Expired / Lapsed
US
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Solid state crosspoint switch
Assignee: Telex Computer Products Inc
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Filing: 1973-09-28
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Granted: 1975-05-13
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Expires: 1993-09-28
Abstract
Abstract A solid state crosspoint switch particularly suited for use in a telephone switching matrix includes two switching transistors. Audio signals are enabled to pass through the crosspoint switch via a low impedance path by driving the two switching transistors into saturation from a gated control circuit responsive to appropriate control signals. Noise immunity is provided by a current regulating switch interposed between the crosspoint switch and the control circuit. Another embodiment includes two switching transistors and two compensating transistors in a balanced bridge configuration to substantially eliminate crosstalk while the switch is open.
Inventors
- 👤 Glenn L Richards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:37
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/42; H04Q3/52; H04Q3/521; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/60; H03K17/62; H03K17/6221
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
204 words
A solid state crosspoint switch for interconnecting a first and second lead with a third and fourth lead, respectively, comprising: two semiconductor devices, each having a controllable path poled for conducting current in the same direction through the interconnection and a control terminal for controlling the amount of current flow therethrough, the current path of a first one of said devices being connected between the first and third leads, the current path of a second one of said devices being connected between the second and fourth leads; and control circuit means connected to the control terminals of said first and second semiconductor devices responsive to switching signals for enabling or disabling both current paths thereof simultaneously, said control circuit means including high impedance current regulating means for providing a substantially fixed current when enabling said first and second semiconductor devices, a flip-flop which is set to enable said current regulating means and reset to disable said current regulating means and first and second switching circuits, said first switching circuit being responsive to a first switching signal for setting said flip-flop and said second switching circuit being responsive to a second switching signal in the presence of the first switching signal for resetting said flipflop.
Claim 2
Dependent Claim
204 words
A solid state crosspoint switch for interconnecting a first and second lead with a third and fourth lead, respectively, comprising: two semiconductor devices, each having a controllable path poled for conducting current in the same direction through the interconnection and a control terminal for controlling the amount of current flow therethrough, the current path of a first one of said devices being connected between the first and third leads, the current path of a second one of said devices being connected between the second and fourth leads; and control circuit means connected to the control terminals of said first and second semiconductor devices responsive to switching signals for enabling or disabling both current paths thereof simultaneously, said control circuit means including high impedance current regulating means for providing a substantially fixed current when enabling said first and second semiconductor devices, a flip-flop which is set to enable said current regulating means and reset to disable said current regulating means and first and second switching circuits, said first switching circuit being responsive to a first switching signal for setting said flip-flop and said second switching circuit being responsive to a second switching signal in the presence of the first switching signal for resetting said flipflop.
Claim 3
Dependent Claim
253 words
A solid state crosspoint switch for respectively interconnecting the tip and ring leads of two balanced telephone circuits used in translating audio signals through a telephone switching network, comprising: two semiconductor devices, each having a controllable current path poled for conducting current in the same direction through the interconnection and a control terminal for controlling the amount of current therethrough, the current path of a first one of said devices being connected between the tip leads of the two circuits and the current path of the second one of said devices being connected between the ring leads of the two circuits; control circuit means connected to the control terminals of said first and second semiconductor devices for providing two control states for enabling and disabling both current paths thereof simultaneously, said control circuit means including high impedance current regulating means for providing a substantially fixed current when enabling said first and second semiconductor devices, a flip-flop which is set to enable said current regulating means and reset to disable said current regulating means and first and second switching circuits, said first switching circuit being responsive to a first switching signal for setting said flip-flop and said second switching circuit being responsive to a second switching signal in the presence of a first switching signal for resetting said flip-flop; and switching circuit means for changing the state of said control circuit means in response to switching pulses applied thereto including storage circuit means for maintaining said state until the next switching pulse is received.
Claim 4
Dependent Claim
253 words
A solid state crosspoint switch for respectively interconnecting the tip and ring leads of two balanced telephone circuits used in translating audio signals through a telephone switching network, comprising: two semiconductor devices, each having a controllable current path poled for conducting current in the same direction through the interconnection and a control terminal for controlling the amount of current therethrough, the current path of a first one of said devices being connected between the tip leads of the two circuits and the current path of the second one of said devices being connected between the ring leads of the two circuits; control circuit means connected to the control terminals of said first and second semiconductor devices for providing two control states for enabling and disabling both current paths thereof simultaneously, said control circuit means including high impedance current regulating means for providing a substantially fixed current when enabling said first and second semiconductor devices, a flip-flop which is set to enable said current regulating means and reset to disable said current regulating means and first and second switching circuits, said first switching circuit being responsive to a first switching signal for setting said flip-flop and said second switching circuit being responsive to a second switching signal in the presence of a first switching signal for resetting said flip-flop; and switching circuit means for changing the state of said control circuit means in response to switching pulses applied thereto including storage circuit means for maintaining said state until the next switching pulse is received.
References Cited (Backward Citations)
US3593296A
Cited
US3789151A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |