Patent US3626316A successfully refreshed from Google Patents.
US3626316A
Expired / Lapsed
US
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Signalling device
Assignee: H B ENGINEERING
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Filing: 1969-12-31
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Granted: 1971-12-07
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Expires: 1989-12-31
Abstract
Abstract A controlled current signalling device for use with transmission lines, said device including a current source adapted to be coupled across the transmission lines and having a high output impedance in comparison to the impedance of transmission lines and modulation means adapted to modulate the current source in accordance with a sensed input signal, said current source adapted to maintain its high output impedance during modulation thereof.
Inventors
- 👤 Raymond S Connell Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:24
CPC Classifications
G; G08; G08B; G08B25/00; G08B25/01; G08B25/08
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
95 words
A signalling device for use with a transmission line having a characteristic impedance comprising a controlled current source having outlet connections to couple it across the transmission line, means for establishing a quiescent DC current flow through said current source, input signal means for linearly modulating with an input signal voltage the current flowing through said current source about its quiescent valve such that output current is proportional to the input voltage, and voltage limit means coupled to said input signal means for limiting input signal voltage to prevent saturation of said controlled current source.
Claim 2
Dependent Claim
95 words
A signalling device for use with a transmission line having a characteristic impedance comprising a controlled current source having outlet connections to couple it across the transmission line, means for establishing a quiescent DC current flow through said current source, input signal means for linearly modulating with an input signal voltage the current flowing through said current source about its quiescent valve such that output current is proportional to the input voltage, and voltage limit means coupled to said input signal means for limiting input signal voltage to prevent saturation of said controlled current source.
Claim 3
Dependent Claim
39 words
A signalling device according to claim 1 wherein degenerative feedback means is provided as part of the current source for limiting changes in current through the current source in the event of noise or voltage changes on the line.
Claim 4
Dependent Claim
25 words
A signalling device according to claim 2 in which said current source continuously conducts a DC quiescent current therethrough when coupled to said transmission line.
Claim 5
Dependent Claim
28 words
A signalling device according to claim 3 in which said means for modulating provides a signal for varying the current through the current source about its quiescent value.
Claim 6
Dependent Claim
37 words
A device according to claim 4 in which said means for modulating provides a sinusoidal signal for dynamically varying the current through the source without substantially reducing the output quiescent or dynamic impedance of the signalling device.
Claim 7
Dependent Claim
65 words
A device according to claim 1 in which said current source comprises a first transistor and a second transistor in series therewith, said second transistor establishing the DC quiescent current flowing through said first transistor and said second transistor being coupled to said input signal means coupled to the second transistor to modulate the current flowing through said first transistor about its DC quiescent valve.
Claim 8
Dependent Claim
39 words
A signalling device according to claim 6 in which a resistor is coupled in series with the second transistor and has a resistance of at least ten times larger than the common base input impedance of the second transistor.
Claim 9
Dependent Claim
43 words
A signalling device according to claim 1 in which said cOntrolled current source is constructed such that it has a dynamic impedance when modulated and connected across the line which is at least ten times larger than the characteristic impedance of the line.
Claim 10
Dependent Claim
27 words
A signalling device according to claim 1 in which voltage limit means is coupled to said input signal means to prevent cutoff of said controlled signal source.
Claim 11
Independent Claim
146 words
A system comprising a transmission line having a characteristic impedance, a DC source coupled to said transmission line, a plurality of controlled current sources each coupled across said transmission line and each powered therefrom, means coupled to each of said controlled current sources and to said line for establishing a continuous DC quiescent current flow through each of said controlled current sources, a different modulation means coupled to each of said controlled current sources, each modulation means providing a modulation signal at a different frequency and each of said modulation means providing input signals for dynamically varying the current flowing through each of said sources about the DC quiescent current flow, and means for maintaining the output impedance of each said current sources at least ten times larger than the characteristic impedance of the transmission line while being modulated by input signals from said modulation means.
Claim 12
Independent Claim
146 words
A system comprising a transmission line having a characteristic impedance, a DC source coupled to said transmission line, a plurality of controlled current sources each coupled across said transmission line and each powered therefrom, means coupled to each of said controlled current sources and to said line for establishing a continuous DC quiescent current flow through each of said controlled current sources, a different modulation means coupled to each of said controlled current sources, each modulation means providing a modulation signal at a different frequency and each of said modulation means providing input signals for dynamically varying the current flowing through each of said sources about the DC quiescent current flow, and means for maintaining the output impedance of each said current sources at least ten times larger than the characteristic impedance of the transmission line while being modulated by input signals from said modulation means.
Claim 13
Dependent Claim
33 words
A system according to claim 10 in which said means for maintaining the output impedance of each of said controlled sources includes means for preventing saturation of each of said controlled current sources.
Claim 14
Dependent Claim
26 words
A system according to claim 11 in which each modulation means for varying the current of each of the sources comprise modulation means providing sinusoidal signals.
Claim 15
Dependent Claim
35 words
A system according to claim 10 in which each of said source includes degenerative feedback means coupled thereto for limiting the effect of line voltage variations upon the DC quiescent current flowing through the sources.
Claim 16
Dependent Claim
138 words
A signalling device for coupling to a transmission line having a characteristic impedance and carrying a DC voltage across it, said device comprising a controlled current source which includes a first transistor coupled in series with a second transistor for controlling the current flow through it, a resistor in series with said first and second transistor for providing negative feedback to limit the DC current flow through both of said transistors when both transistors are coupled to the transmission line, a biasing network coupled to said transmission line for initiating DC current flow through said transistors, an oscillator network for applying a modulating voltage to said second transistor to modulate the current flow through said first and second transistors, said oscillator network including means for limiting the modulating voltage to prevent saturation of the first and second transistors.
Claim 17
Dependent Claim
138 words
A signalling device for coupling to a transmission line having a characteristic impedance and carrying a DC voltage across it, said device comprising a controlled current source which includes a first transistor coupled in series with a second transistor for controlling the current flow through it, a resistor in series with said first and second transistor for providing negative feedback to limit the DC current flow through both of said transistors when both transistors are coupled to the transmission line, a biasing network coupled to said transmission line for initiating DC current flow through said transistors, an oscillator network for applying a modulating voltage to said second transistor to modulate the current flow through said first and second transistors, said oscillator network including means for limiting the modulating voltage to prevent saturation of the first and second transistors.
Claim 18
Dependent Claim
49 words
A device according to claim 14 in which a diode is coupled in series between said first and second transistors and in which the biasing circuit operates to first initiate current flow through said second transistor thereby initiating current flow through said diode to turn said first transistor on.
Claim 19
Dependent Claim
72 words
A device according to claim 14 in which said oscillator network comprises a transducer, means coupled to line for biasing the transducer, a third transistor coupled to said transducer and to said second transistor, means for providing positive feedback between the third transistor and the transducer, and means for loading the third transistor with a fourth transistor in series therewith to limit power consumption by raising the impedance seen by the transducer.
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) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |