GB710600A - Improvements in or relating to voice frequency signalling system - Google Patents
Improvements in or relating to voice frequency signalling systemInfo
- Publication number
- GB710600A GB710600A GB14314/52A GB1431452A GB710600A GB 710600 A GB710600 A GB 710600A GB 14314/52 A GB14314/52 A GB 14314/52A GB 1431452 A GB1431452 A GB 1431452A GB 710600 A GB710600 A GB 710600A
- Authority
- GB
- United Kingdom
- Prior art keywords
- circuit
- signal
- frequency
- valve
- transformer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/18—Electrical details
- H04Q1/30—Signalling arrangements; Manipulation of signalling currents
- H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
- H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
- H04Q1/45—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Noise Elimination (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
710,600. Voice-frequency signal receivers. STANDARD TELEPHONE & CABLES, Ltd. June 6, 1952 [July 10, 1951], No. 14314/52. Class 40 (4) A receiver for two voice-frequency signals has a separate receiving circuit for each signal, the unwanted signal in each circuit being suppressed by the frequency-selective negative feedback of an amplifying valve which has cathode circuit tuned to the unwanted frequency. In the arrangement described the receiver descriminates between pure signals and signals occurring simultaneously with other frequencies. As shown, incoming signals at a transformer T1 are applied over a buffer amplifier V1 and. a transformer T2 to a fourwire terminating set or a two-wire line. Signals from transformer T1 are also applied to valve V2 which has its cathode circuit tuned by a rejector circuit L1, C1 so that one signal frequency and any spurious frequencies are fully amplified and supplied to a signal receiving circuit over a transformer T3. The unwanted signal frequency suppressed by valve V2 is obtained from the rejector circuit L1, C1 and energizes a further valve V3 which is tuned by L2, C2 in its cathode circuit and suppresses only the signal frequency acceptable to valve V2. The output of V3 consists primarily of a single signal frequency and is applied to a second receiving circuit over a transformer T4. In the receiving circuits the two signal frequencies each control a biased relay X1, X2 over an acceptor circuit C3, L3 or C4, L4 and a rectifier W1 or W2. Spurious frequencies present in the output of valve V2 are rectified at W3 and energize guard windings a2, b2 on the two relays, the signal frequency being eliminated by a rejector circuit C5, L5. The valves V2 and V3 have high mutual conductances and function as-limiters, the resultant harmonic distortion being filtered off by shunt condensers C6 and C7 respectively.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT319073X | 1951-07-10 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB710600A true GB710600A (en) | 1954-06-16 |
Family
ID=11234479
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB14314/52A Expired GB710600A (en) | 1951-07-10 | 1952-06-06 | Improvements in or relating to voice frequency signalling system |
Country Status (3)
Country | Link |
---|---|
BE (1) | BE512709A (en) |
CH (1) | CH319073A (en) |
GB (1) | GB710600A (en) |
-
0
- BE BE512709D patent/BE512709A/xx unknown
-
1952
- 1952-06-06 GB GB14314/52A patent/GB710600A/en not_active Expired
- 1952-07-08 CH CH319073D patent/CH319073A/en unknown
Also Published As
Publication number | Publication date |
---|---|
BE512709A (en) | |
CH319073A (en) | 1957-01-31 |
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