GB594160A - Improvements relating to electric signalling systems - Google Patents
Improvements relating to electric signalling systemsInfo
- Publication number
- GB594160A GB594160A GB1191445A GB1191445A GB594160A GB 594160 A GB594160 A GB 594160A GB 1191445 A GB1191445 A GB 1191445A GB 1191445 A GB1191445 A GB 1191445A GB 594160 A GB594160 A GB 594160A
- Authority
- GB
- United Kingdom
- Prior art keywords
- resistance
- trl
- signal
- iii
- output
- 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
- 230000011664 signaling Effects 0.000 title abstract 5
- 230000001808 coupling Effects 0.000 abstract 5
- 238000010168 coupling process Methods 0.000 abstract 5
- 238000005859 coupling reaction Methods 0.000 abstract 5
- 230000000694 effects Effects 0.000 abstract 2
- 101700027021 trxB Proteins 0.000 abstract 2
- 238000004804 winding Methods 0.000 abstract 2
- 230000005540 biological transmission Effects 0.000 abstract 1
- 239000000969 carrier Substances 0.000 abstract 1
- 230000000875 corresponding Effects 0.000 abstract 1
- 230000000051 modifying Effects 0.000 abstract 1
- 230000001629 suppression Effects 0.000 abstract 1
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
- H04Q1/446—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency
- H04Q1/4465—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency the same frequency being used for all signalling information, e.g. A.C. nr.9 system
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Devices For Supply Of Signal Current (AREA)
Abstract
594,160. Electric signalling systems. SIEMENS BROS. & CO., Ltd., CRUTCH, L. S., MOLE, J. H., and NEWMAN, W. C. May 11, 1945, No. 11914. [Class 40 (iv)J [Also in Group XL] In an electric signalling system, such as a telephone system, using alternating current for signalling, the input and output circuits TRL, TRC of a limiting device LIM are linked by a first coupling including TRL(II), and a second coupling TRL(III) connected in opposition to the output TRC so as to give, by virtue of their special characteristics, a combined output characteristic in which there is no substantial increase in output for increases of input above a critical value. The first coupling comprises winding TRL(II), a series resistance YC and an output shunt arm comprising equal resistances YA, YB and oppositely connected rectilier elements RA, RB biassed by a suitable battery current through resistance YD. The characteristic of this coupling comprises a comparatively steep first portion and a less steep second portion. The second coupling consists in winding TRL(III) which has a linear characteristic. In alternative arrangements, either the windings TRL(II), (III) may be continuous or a resistance and capacity may be inserted between YC and the rectifier elements and the resistance YB reduced to zero. The limiter is described in conjunction with a signal responsive apparatus suitable for use when alternating currents of two separate speech frequencies are used for the transmission of calling and supervisory signals over a conversational circuit. Low impedance highspeed relays X, Y are normally operated and each relay is released when the anode current of the corresponding pentode VA or VB drops on receipt of a pure signal of the appropriate frequency. The normal control grid is given a positive bias by connection to positive battery through resistance YPX. The suppressor grid is used for control purposes and is given a negative bias which is controlled by a non-linear ballast resistance BRX in the cathode lead. The screen grid circuit includes the primary windings of transformers TRX, TRXB, the former sharply tuned and the latter broadly tuned to the same signalling frequency. The signal through TRX(II) and a voltage doubling rectifier RX produces a potential difference across the resistance YX which tends to reduce the anode current to release X. This voltage is countered by a similar potential difference across YXG produced by rectifier RXG according to the differential effects of TRX(III) and TRXB. For a pure signal, this effect is zero and relay X releases. The alternating current signals may be transmitted as modulations on a carrier current. The Provisional Specification states that the signal discriminating arrangements described in Specification 594,159 may be employed and that the circuits may be so arranged that the signal relay is operated by a signal, being normally released.
Publications (1)
Publication Number | Publication Date |
---|---|
GB594160A true GB594160A (en) | 1947-11-04 |
Family
ID=1713411
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1191445A Expired GB594160A (en) | 1945-05-11 | Improvements relating to electric signalling systems |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB594160A (en) |
-
1945
- 1945-05-11 GB GB1191445A patent/GB594160A/en not_active Expired
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