Patent US1866989A successfully refreshed from Google Patents.
US3789151A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid state crosspoint switch
Assignee: Telex Computer Products Inc
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Filing: 1972-03-06
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Granted: 1974-01-29
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Expires: 1992-03-06
Abstract
Abstract A solid state crosspoint switch particularly suited for use in a telephone switching matrix utilizes two switching transistors and two compensating transistors in a balanced bridge configuration to substantially eliminate crosstalk while the switch is effectively open (all four transistors cut off to provide a high impedance for blocking the passage of audio signals therethrough). 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.
Inventors
- 👤 G Richards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:05
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: 12
Claim 1
Independent Claim
197 words
A solid state crosspoint switch for interconnecting a first and second lead with a third and fourth lead, respectively, comprising: four 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 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, the current path of a third one of said devices being connected between the first and fourth leads, and the current path of the fourth one of said devices being connected between the second and third leads; 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, and circuit means connected to the control terminals of said third and fourth devices for disabling the current paths thereof.
Claim 2
Dependent Claim
197 words
A solid state crosspoint switch for interconnecting a first and second lead with a third and fourth lead, respectively, comprising: four 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 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, the current path of a third one of said devices being connected between the first and fourth leads, and the current path of the fourth one of said devices being connected between the second and third leads; 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, and circuit means connected to the control terminals of said third and fourth devices for disabling the current paths thereof.
Claim 3
Dependent Claim
27 words
The solid state switch of claim 1 wherein said control circuit means is repsonsive to a first switching signal for enabling said first and second semiconductor devices.
Claim 4
Dependent Claim
19 words
The solid state switch of claim 2 wherein said first switching signal consists of at least one momentary pulse.
Claim 5
Dependent Claim
27 words
The solid state switch of claim 2 wherein said control circuit means is responsive to a second switching signal for disabling said first and second semiconductor devices.
Claim 6
Dependent Claim
20 words
The solid state switch of claim 4 wherein said second switching signal consists of at least two coincident momentary pulses.
Claim 7
Dependent Claim
42 words
The solid state switch of claim 4 wherein said control circuit means includes storage circuit means which is set by said first switching signal and reset by said second switching signal for respectively enabling and disabling said first and second semiconductor devices.
Claim 8
Dependent Claim
38 words
The solid state switch of claim 4 wherein said control circuit means drives said first and second semiconductor devices into saturation in response to said first switching signal and into cutoff in response to said second switching signal.
Claim 9
Dependent Claim
270 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: four 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 flow therethrough, the current path of a first one of said devices being connected between the tip leads of the two circuits, the current path of a second one of said devices being connected between the rings leads of the two circuits, the current path of a third one of said devices being connected between the tip lead of one of the two circuits and the ring lead of the other circuit and the current path of the fourth one of said devices being connected between the ring lead of the first mentioned circuit and the tip lead of the other circuit; control circuit means connected to the control terminals of said first and second semiconductor devices for providing two control states 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; 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, and control circuit means connected to the control terminals of said third and fourth semiconductor devices for disabling the current paths thereof.
Claim 10
Dependent Claim
270 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: four 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 flow therethrough, the current path of a first one of said devices being connected between the tip leads of the two circuits, the current path of a second one of said devices being connected between the rings leads of the two circuits, the current path of a third one of said devices being connected between the tip lead of one of the two circuits and the ring lead of the other circuit and the current path of the fourth one of said devices being connected between the ring lead of the first mentioned circuit and the tip lead of the other circuit; control circuit means connected to the control terminals of said first and second semiconductor devices for providing two control states 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; 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, and control circuit means connected to the control terminals of said third and fourth semiconductor devices for disabling the current paths thereof.
Claim 11
Dependent Claim
76 words
The solid state crosspoint switch of claim 1 wherein said control circuit means includes a flip-flop which is set to enable said regulating means and reset to disable said 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 flip-flop.
Claim 12
Dependent Claim
76 words
The solid state crosspoint switch of claim 8 wherein said control circuit means includes a flip-flop which is set to enable said regulating means and reset to disable said 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 flip-flop.
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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |