Patent US3614318A successfully refreshed from Google Patents.
US3614318A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data transmission system
Assignee: International Business Machines Corp
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Filing: 1969-08-06
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Granted: 1971-10-19
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Expires: 1989-08-06
Abstract
Abstract A transmitter and receiver for use in a two-wire transmission network in which a central station controls data flow in both directions by controlling the polarity of the line and the transmitter and receiver each include a plurality of polarity sensitive switching stages in which adjacent stages have opposite polarity orientation and each of the stages is turned ''''on'''' by one polarity orientation and ''''off'''' by the opposite polarity orientation on the transmission line.
Inventors
- 👤 Ulrich Klose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:13
CPC Classifications
H; H04; H04L; H04L25/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
218 words
A communications terminal for communicating over a twoconductor transmission medium in response to successive polarity changes of the two-conductor medium and comprising: a plurality of switching stages each including, a switching element having a first state in which the switch is off and passes no current and a second state in which the switch is on and passes current in one direction only, and a control means for controlling said switching element, first means connecting said switching stages including the switching elements in parallel with each other between the two conductors of the transmission medium, said switching elements being arranged so that at least half are connected to pass current in one direction and the remainder are connected to pass current in the opposite direction, second means associated with each stage for exclusively connecting the control means of all but one switching stage to one of the other oppositely connected stages, each said control means responding to conduction in the connected other stage for turning the controlled stage on when the polarity of the transmission medium and the switch element of the controlled stage correspond, and selectively operable means connected to said one switching stage for turning said one stage on when the polarity of the transmission medium and the switch element of the said one stage correspond.
Claim 2
Dependent Claim
218 words
A communications terminal for communicating over a twoconductor transmission medium in response to successive polarity changes of the two-conductor medium and comprising: a plurality of switching stages each including, a switching element having a first state in which the switch is off and passes no current and a second state in which the switch is on and passes current in one direction only, and a control means for controlling said switching element, first means connecting said switching stages including the switching elements in parallel with each other between the two conductors of the transmission medium, said switching elements being arranged so that at least half are connected to pass current in one direction and the remainder are connected to pass current in the opposite direction, second means associated with each stage for exclusively connecting the control means of all but one switching stage to one of the other oppositely connected stages, each said control means responding to conduction in the connected other stage for turning the controlled stage on when the polarity of the transmission medium and the switch element of the controlled stage correspond, and selectively operable means connected to said one switching stage for turning said one stage on when the polarity of the transmission medium and the switch element of the said one stage correspond.
Claim 3
Dependent Claim
48 words
A communications terminal as set forth in claim 1 in which said switching elements each include a silicon controlled switch having an anode element, a cathode element and at least one control element whereby the silicon controlled switch assumes a low-impedance state when the elements are properly biased.
Claim 4
Dependent Claim
94 words
A communications terminal as set forth in claim 1 in which said control means includes capacitor means including a charging circuit connected to the said other stage via the said second means for charging the said capacitor means via the switching element of the said other stage when the said other stage is in its on state, and means connecting the capacitor means to the associated control element of the silicon controlled switch for turning said switch on when the polarities of the medium and the switch correspond and the capacitor means are charged.
Claim 5
Dependent Claim
71 words
A communications terminal as set forth in claim 3 in which the selectively operable means connected to the said one switching stage includes a voltage polarity and magnitude sensitive means responsive to the voltage polarity and magnitude of the two-conductor medium for supplying bias voltage to the control element of the silicon controlled switch for turning said switch on when the magnitude and polarity of the medium attain a predetermined state.
Claim 6
Dependent Claim
81 words
A communications terminal as set forth in claim 4 for operation as a transmitter in response to successive polarity changes of equal voltage magnitude on the two-conductor medium and in which each of said stages includes an impedance means in series with the switching element, some of said iMpedance means being selectively setable to more than one impedance value whereby the impedance between the two conductors of the medium is determined by the impedance selected or provided for a turned-on stage.
Claim 7
Dependent Claim
35 words
A communications terminal as set forth in claim 5 in which said selectively setable impedance means may be set to one of two values corresponding to the 1 and 0 values of the binary code.
Claim 8
Dependent Claim
106 words
A communications terminal as set forth in claim 4 for accepting and storing sequential information supplied over the two-conductor transmission medium and in which two successive polarity changes are utilized to transmit one bit of information with the voltage level of the first polarity orientation of each pair assuming a first level to transmit a one bit in the binary code and a second level to transmit a zero bit in the binary code, each said stage in said terminal including means responsive to the conductive condition of the silicon controlled switch associated with the stage for providing indicia of the conductive state of the stage.
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) | 1974-10-18 | 1975-04-19 | 1975-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-18 | 1979-04-19 | 1979-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-18 | 1983-04-19 | 1983-10-19 | $7700.00 | Window Closed / Lapsed |