US3868484A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power feed arrangement for communication systems
Assignee: Post Office
•
Filing: 1972-12-11
•
Granted: 1975-02-25
•
Expires: 1992-12-11
Abstract
Abstract A power feed arrangement provided as a safety measure in a communications system of the type in which two terminal stations are connected by at least one transmission path which transmits information signals from one of the stations to the other through information signal repeating means. Two sources (one at each station) supply energizing current along the transmission path to the repeating means, and, in addition, a monitoring signal is generated at each station to be transmitted along the transmission path to the other station and detected at that other station. If one of the monitoring signals is not detected, the energizing current supply sources are disconnected from the transmission path. Provision is made to ensure that the supply sources can only be connected to the transmission path following successful transmission and detection of the monitoring signals, and for testing the current output of the sources and the impedance of the transmission path prior to operation of the system.
Inventors
- 👤 Leslie John Bolton
- 👤 Brian Hall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:43
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/02; H01M4/64; H01M4/66; H01M4/68; C; C22; C22C; C22C11/00; C22C11/02; H02; H02H; H02H1/00; H02H1/0007; H02H1/003; H02H1/0061; H02H1/0076; H02H11/00; H02H11/005; H04; H04B; H04B3/00; H04B3/02; H04B3/44; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
200 words
A power feed arrangement for a communications system which includes two terminal stations; a transmission path connecting the terminal stations to transmit information signals from one of the stations to the other; a respective energizing current supply source at each station, and information signal repeating means connected in the transmission path and energizable by current supplied along the transmission path from the energizing current supply sources, said power feed arrangement including, at each station: a monitoring signal generator operable to apply, to the transmission path, a monitoring signal which is to be transmitted to the Other station, A first detector connected to the transmission path to receive the monitoring signal transmitted to that station from the other station, said first detector being operable, in response to a failure to receive a monitoring signal from the other station, to disconnect the energizing current supply sources from the transmission path, and a second detector connected to the transmission path to receive the monitoring signal applied to the transmission path at that station, the second detector being operable, in response to a failure to receive the monitoring signal applied at that station, to disconnect the energizing current supply sources from the transmission path.
Claim 2
Dependent Claim
200 words
A power feed arrangement for a communications system which includes two terminal stations; a transmission path connecting the terminal stations to transmit information signals from one of the stations to the other; a respective energizing current supply source at each station, and information signal repeating means connected in the transmission path and energizable by current supplied along the transmission path from the energizing current supply sources, said power feed arrangement including, at each station: a monitoring signal generator operable to apply, to the transmission path, a monitoring signal which is to be transmitted to the Other station, A first detector connected to the transmission path to receive the monitoring signal transmitted to that station from the other station, said first detector being operable, in response to a failure to receive a monitoring signal from the other station, to disconnect the energizing current supply sources from the transmission path, and a second detector connected to the transmission path to receive the monitoring signal applied to the transmission path at that station, the second detector being operable, in response to a failure to receive the monitoring signal applied at that station, to disconnect the energizing current supply sources from the transmission path.
Claim 3
Dependent Claim
44 words
A power feed arrangement as claimed in claim 1, including means operable to connect the energizing current supply sources to the transmission path only in response to the detection, at both stations, of the monitoring signals applied to the transmission path at both stations.
Claim 4
Dependent Claim
31 words
A power feed arrangement as claimed in claim 1, in which each detector is operable to disconnect, from the transmission path, the energizing current supply source located at the same station.
Claim 5
Dependent Claim
38 words
A power feed arrangement as claimed in claim 3, in which each detector is operable simultaneously to terminate the application of a monitoring signal to the transmission path by the monitoring signal generator located at the same station.
Claim 6
Dependent Claim
31 words
A power feed arrangement as claimed in claim 1, including means operable to test the current output of the energizing current supply sources prior to operation of the monitoring signal generators.
Claim 7
Dependent Claim
26 words
A power feed arrangement as claimed in claim 5, in which the current testing means is operable in response to energization of each current supply source.
Claim 8
Dependent Claim
61 words
A power feed arrangement as claimed in claim 5, in which the current testing means includes switching means operable to connect each current supply source to an electrical load representative of the load that would normally be presented to that source by the transmission path, and a current sensor for measuring the current supplied by said source to said representative load.
Claim 9
Dependent Claim
47 words
A power feed arrangement as claimed in claim 5, in which the monitoring signal generators are operable to apply monitoring signals to the transmission path only in response to the detection, by the current testing means, of a normal current output from the energizing current supply sources.
Claim 10
Dependent Claim
29 words
A power feed arrangement as claimed in claim 1, including means operable to test the electrical impedance of the transmission path prior to operation of the monitoring signal generators.
Claim 11
Dependent Claim
28 words
A power feed arrangement as claimed in claim 9, in which the impedance testing means is operable in response to energization of one of the current supply sources.
Claim 12
Dependent Claim
42 words
A power feed arrangement as claimed in claim 9, in which the impedance testing means includes switching means operable to connect the transmission path, through a current sensor, to a test source of substantially lower voltage than the energizing current supply sources.
Claim 13
Dependent Claim
46 words
A power feed arrangement as claimed in claim 9, in which the monitoring signal generators are operable to apply monitoring signals to the transmission path only in response to the detection, by the impedance testing means, of a normal electrical impedance condition in the transmission path.
Claim 14
Dependent Claim
48 words
A power feed arrangement as claimed in claim 1, including a respective protector for each current supply source, the protector being operable in response to a voltage greater than a predetermined value at the current supply source output to disconnect the current supply source from the transmission path.
Claim 15
Dependent Claim
33 words
A communications system which includes a power feed arrangement as claimed in claim 1, and in which the transmission path includes an electrical conductor connected to transmit both information signals and monitoring signals.
Claim 16
Dependent Claim
40 words
A communications system as claimed in claim 14, including, at each repeating mEans, a discriminating network connected in the transmission path for separating the monitoring signals from the information signals to apply only the information signals to the repeating means.
Claim 17
Dependent Claim
45 words
A communications system which includes a power feed arrangement as claimed in claim 1, and in which the transmission path includes an electrical conductor which is connected to transmit the monitoring signals and which is separate from the conductor connected to transmit the information signals.
Claim 18
Dependent Claim
37 words
A communications system which includes two transmission paths each having a respective power feed arrangement as claimed in claim 1, the transmission paths connecting two terminal stations to transmit information signals in opposite directions between the stations.
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) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |