Patent US3832489A successfully refreshed from Google Patents.
US3832489A
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US
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Bidirectional bus repeater
Assignee: Digital Equipment Corp
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Filing: 1973-02-26
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Granted: 1974-08-27
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Expires: 1993-02-26
Abstract
Abstract A bus repeater circuit for interconnecting first and second corresponding transmission lines for first and second adjacent bidirectional electrical bus sections. The bus repeater circuit includes first and second current sensors associated with each transmission line to apply a bipolar signal to first and second amplifiers respectively. Output signals from a given sensor of a first polarity indicate that the associated transmission line is transmitting a signal. The associated amplifier couples that signal to the other bus wire. Signals of a second polarity indicate that the associated bus transmission line is not transmitting a signal to the repeater and the associated amplifier provides a corresponding signal, thereby avoiding a latched condition.
Inventors
- 👤 R Krishna
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:47
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/38; G06F13/40; G06F13/4004; G06F13/4027; G06F13/4045; H; H04; H04L; H04L25/00; H04L25/02; H04L25/20; H04L25/24; H04L5/00; H04L5/14; H04L5/1423
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
177 words
A bus repeater adapted for connection in series between a pair of corresponding transmission lines in adjacent sections of a bus, said repeater comprising: A. a first terminal adapted for connection to one transmission line in one bus section and a second terminal adapted for connection to a corresponding transmission line in the adjacent bus section, B. first and second termination means connected to each of said first and second terminals, respectively, each of said termination means including current sensing means connected to the corresponding terminal and terminating the transmission line connected thereto in substantially its characteristic impedance, C. first and second amplifier means connected to said current sensing means in said first and second termination means, respectively, each amplifier means generating an amplified data signal in response to an incoming signal from said respective current sensing means, the other of said sensing means coupling the amplifier output signal to the other transmission line and applying to its corresponding amplifier a signal of the opposite polarity to that of an incoming signal on said other transmission line.
Claim 2
Dependent Claim
177 words
A bus repeater adapted for connection in series between a pair of corresponding transmission lines in adjacent sections of a bus, said repeater comprising: A. a first terminal adapted for connection to one transmission line in one bus section and a second terminal adapted for connection to a corresponding transmission line in the adjacent bus section, B. first and second termination means connected to each of said first and second terminals, respectively, each of said termination means including current sensing means connected to the corresponding terminal and terminating the transmission line connected thereto in substantially its characteristic impedance, C. first and second amplifier means connected to said current sensing means in said first and second termination means, respectively, each amplifier means generating an amplified data signal in response to an incoming signal from said respective current sensing means, the other of said sensing means coupling the amplifier output signal to the other transmission line and applying to its corresponding amplifier a signal of the opposite polarity to that of an incoming signal on said other transmission line.
Claim 3
Dependent Claim
45 words
A bus repeater circuit as recited in claim 1 wherein each of said amplifier means comprises a differential amplifier and an inverter connected to invert the output of said differential amplifier, said differential amplifier having inverting and non-inverting inputs connected across asid current sensing means.
Claim 4
Dependent Claim
86 words
A bus repeater circuit as recited in claim 1 wherein each termination means includes a first and second resistors in series, said first resistor connected to a terminal and constituting a current sensor and said second resistor being connected to a source of positive potential, thereby establishing a quiescent voltage signal at the terminal, the resistance of said first resistor being significantly less than that of said second resistor and said second resistor having a resistance substantially equal to the characteristic impedance of the transmission line.
Claim 5
Dependent Claim
70 words
A bus repeater circuit as recited in claim 3 wherein each amplifier means includes a differential amplifier and inverter in cascade, said differential amplifier having inverting and noninverting inputs connected across a corresponding first resistor with the inverting input being connected to a corresponding terminal, the output of the inverter being connected to the junction of the first and second resistors which are connected in series with the other terminal.
Claim 6
Dependent Claim
167 words
A bus repeater circuit for connecting corresponding transmission lines in first and second adjacent bus sections, said bus repeater circuit comprising: A. a first terminal for connection to a transmission line in the first bus section, B. a second terminal for connection to a corresponding transmission line in the second bus section, said bus repeater circuit being in series between corresponding transmission lines, C. a first termination circuit comprising, in series, a first termination resistor and a first current sensing resistor connected to said first terminal, D. a second termination circuit comprising, in series, a second termination resistor and a second current sensing resistor connected to said second terminal, E. first differential amplifying means with inputs connected across first current sensing resistor and an output coupled with the junction of the second termination in current seNsing resistors, and F. second differential amplifying means with inputs connected across said second current sensing resistor and an output coupled to the junction of said first termination in current sensing resistors.
Claim 7
Dependent Claim
167 words
A bus repeater circuit for connecting corresponding transmission lines in first and second adjacent bus sections, said bus repeater circuit comprising: A. a first terminal for connection to a transmission line in the first bus section, B. a second terminal for connection to a corresponding transmission line in the second bus section, said bus repeater circuit being in series between corresponding transmission lines, C. a first termination circuit comprising, in series, a first termination resistor and a first current sensing resistor connected to said first terminal, D. a second termination circuit comprising, in series, a second termination resistor and a second current sensing resistor connected to said second terminal, E. first differential amplifying means with inputs connected across first current sensing resistor and an output coupled with the junction of the second termination in current seNsing resistors, and F. second differential amplifying means with inputs connected across said second current sensing resistor and an output coupled to the junction of said first termination in current sensing resistors.
Claim 8
Dependent Claim
40 words
A bus repeater as recited in claim 5 wherein each of said differential amplifying inputs include inverting and non-inverting inputs, said inverting inputs of said first and second differential amplifying means being connected to the first and second terminals respectively.
References Cited (Backward Citations)
US3612781A
Cited
US3673326A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |