US3705418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital pulse signal transmission circuit
Assignee: Fujitsu Ltd
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Filing: 1971-06-18
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Granted: 1972-12-05
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Expires: 1991-06-18
Abstract
Abstract A digital pulse signal transmission line circuit is disclosed whose impedance is matched to the output impedance of the transmitter circuit for both an outflow current and an inflow current. An active element such as a transistor is connected in parallel with the input to the transmission line and a unidirectional switching means is connected in series with said transmission line so as to switch the transistor. When the outflow current flows, the unidirectional switching means generates a forward voltage drop due to said outflow current and this voltage drop cuts off the transistor. When the inflow current flows, the unidirectional switching means is cut off and said inflow current flows through the transistor which becomes conductive and causes the output impedance to decrease. As a result of this, the impedance of the digital pulse signal transmission line circuit is always matched to the output impedance of the transmitter circuit.
Inventors
- 👤 Norito Yoshitake
- 👤 Ryoji Imazeki
- 👤 Hiroshi Ishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:27
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/0264; H04L25/028; H04L25/12; H04L25/0266; H04L25/0278
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
175 words
A digital pulse signal transmission circuit comprising a transmission line of said circuit insulated from ground in which a digital data signal is applied to the oscillator circuit, said oscillator circuit being modulated by said digital data signal, the output of said oscillator circuit being supplied via a transformer to a full wave rectifier circuit, the output DC signal of said full wave rectifier circuit being divided by a series resistor and a parallel resistor, the output of said parallel resistor being transmitted to the transmission line, an active element connected between the terminals of said parallel resistor, a unidirectional switching means for controlling said active element during the time said output DC signal is sent, said unidirectional switching means producing a forward voltage drop, said forward voltage drop cutting off said active element, and during the time no DC output signal is sent said unidirectional switching means being cut off, and then said active element being put into a conductive state by a discharging current from the electronic charge stored in said transmission line.
Claim 2
Dependent Claim
175 words
A digital pulse signal transmission circuit comprising a transmission line of said circuit insulated from ground in which a digital data signal is applied to the oscillator circuit, said oscillator circuit being modulated by said digital data signal, the output of said oscillator circuit being supplied via a transformer to a full wave rectifier circuit, the output DC signal of said full wave rectifier circuit being divided by a series resistor and a parallel resistor, the output of said parallel resistor being transmitted to the transmission line, an active element connected between the terminals of said parallel resistor, a unidirectional switching means for controlling said active element during the time said output DC signal is sent, said unidirectional switching means producing a forward voltage drop, said forward voltage drop cutting off said active element, and during the time no DC output signal is sent said unidirectional switching means being cut off, and then said active element being put into a conductive state by a discharging current from the electronic charge stored in said transmission line.
Claim 3
Dependent Claim
25 words
A digital pulse signal transmission circuit according to claim 1, wherein said active element comprises a transistor and said unidirectional switching means comprises a diode.
Claim 4
Dependent Claim
130 words
A signalling circuit in which a pulse is transmitted from a transmission circuit across whose output a first resistance element is coupled and in series therewith a second resistance element is coupled, said pulse being transmitted from said output via a transmission line to a receiving circuit, comprising (a) a variable impedance switching means coupled in parallel with said first element and arranged to be non-conductive in response to outflow of current through said transmission line, and (b) a unidirectional switching means coupled to said variable impedance means and arranged to be conductive in response to said outflow whereupon it cuts off said variable impedance means, said unidirectional means being rendered non-conductive by reverse flow of current through said line whereupon said reverse flow renders said variable impendance means conductive.
Claim 5
Dependent Claim
130 words
A signalling circuit in which a pulse is transmitted from a transmission circuit across whose output a first resistance element is coupled and in series therewith a second resistance element is coupled, said pulse being transmitted from said output via a transmission line to a receiving circuit, comprising (a) a variable impedance switching means coupled in parallel with said first element and arranged to be non-conductive in response to outflow of current through said transmission line, and (b) a unidirectional switching means coupled to said variable impedance means and arranged to be conductive in response to said outflow whereupon it cuts off said variable impedance means, said unidirectional means being rendered non-conductive by reverse flow of current through said line whereupon said reverse flow renders said variable impendance means conductive.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |