GB582177A - Multiplex high frequency electrical pulse signalling systems - Google Patents
Multiplex high frequency electrical pulse signalling systemsInfo
- Publication number
- GB582177A GB582177A GB558743A GB558743A GB582177A GB 582177 A GB582177 A GB 582177A GB 558743 A GB558743 A GB 558743A GB 558743 A GB558743 A GB 558743A GB 582177 A GB582177 A GB 582177A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pulses
- channel
- channels
- pulse
- valve
- 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
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/04—Distributors combined with modulators or demodulators
- H04J3/042—Distributors with electron or gas discharge tubes
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/04—Distributors combined with modulators or demodulators
- H04J3/045—Distributors with CRT
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Noise Elimination (AREA)
Abstract
582,177. Pulse modulation; multiplex systems. STANDARD TELEPHONES & CABLES. Ltd., CHATTERJEA, P. K., and HOUGHTON, L. W. April 7, 1943, No. 5587. [Class 40 (v)] In a multi-channel pulse signalling system of the kind in which the channels a ... d, Fig. 1, are interlaced sequencies (e) of phase-modulated pulses, the channels are separated at the receiver by deriving from consecutive pairs a, b; c, d, &c. further pulses (f) of durations equal to the time interval between the respective pairs, differentiating the pulses (f) to obtain the pulse form (g) and then separating the positive and negative pulses from (g) to obtain a sequence (h) in which only the channels a, c are reprosented, and a sequence (i) in which only b, d are represented. A repetition of the process results in complete separation of all the channels. The system is shown in Fig. 1 with four channels, but the number may be any power of two. Fig. 3 shows the general arrangement, the received pulses (e) being applied to a circuit 73 which converts them to the form (f); they are then differentiated and separated into the trains (h), (i) by limiters 74, 75. The process is repeated for each of these trains to give the pulses related to each channel at the terminals 82 ... 85. In order to secure correct chanelling, despite the presence of additional interference pulses, or the absence of some of the signal pulses, several methods may be employed. (a) The pulses of one channel (say No. 1) may carry a characteristic modulation, to which a control unit 88 responds. When this characteristic is present at the unit 88, a correcting unit 89 is maintained inoperative. Should the characteristic modulation not be received in channel (1), the unit 89 comes into action to supply or eliminate one or more pulses until correct working is again attained. A similar control unit 86, 87 is arranged at the output of the preceding separation stage 74 traversed by the pulses of channel 1. (b) Alternatively, a distinctive modulation may be provided for each channel, and at the receiver, the output from channel (1) may be applied to a selector 104, Fig. 11, which may be a frequency filter in the case when the distinctive modulations are of different frequency. The output from the filter is rectified and applied as bias to a valve 110 which serves to eliminate a pulse and to a valve. 129 which serves to insert an extra pulse. When the system is working normally, the valve 110 merely allows the received pulses to pass unchanged to the next stage BB, but should an interference pulse put the channels out of synchronism, the filter output changes, in the negative direction, reducing the saturation bias on the valve 110 and causing the pulses passed to the stage BB to fall off in amplitude until a pulse fails to operate that stage. If the want of synchronism is in the opposite sense due to missing pulses, the output from the filter 104 changes in the positive direction, so as to remove a cut-off bias from the amplifier valve 129, which thereupon transmits one or more pulses from the valve 110<1> through a delay network DN to the stage BB. The missing pulses are thus restored and the channels again brought into synchronism. In Fig. 11, the stages BB join up consecutive pairs of pulses to form pulses of variable duration as at f, Fig. 1, and the differentiation process necessary to produce the form g is effected by capacities C1 and resistances R. The valves 98, 99 effect the separation into the forms h, i and the valves 100 ... 103 the further separation required at the next stage. (c) The channel synchronization may also be effected by using at the stages BB multi-vibrator circuits having a free frequency corresponding to maximum permissible time modulation of the pulses. (d) By averaging or integrating the series of received pulses, any loss of signal pulses or any additional interfering pulses may be made to provide a control voltage for effecting the desired correction.
Priority Applications (9)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR962120D FR962120A (en) | 1943-04-07 | ||
BE472934D BE472934A (en) | 1943-04-07 | ||
GB18640/44A GB582198A (en) | 1943-04-07 | 1943-04-07 | Improvements in or relating to multiplex high frequency electrical pulse signalling systems |
GB558743A GB582177A (en) | 1943-04-07 | 1943-04-07 | Multiplex high frequency electrical pulse signalling systems |
GB18641/44A GB582199A (en) | 1943-04-07 | 1943-04-07 | Improvements in or relating to multiplex high frequency electrical pulse signalling systems |
US526566A US2447233A (en) | 1943-04-07 | 1944-03-15 | Pulse time modulation multiplex receiver |
US618332A US2523279A (en) | 1943-04-07 | 1945-09-24 | Multiplex high-frequency electrical pulse signaling system |
US620818A US2454773A (en) | 1943-04-07 | 1945-10-06 | Pulse multiplex transmitter employing a cathode-ray tube time modulator |
ES176834A ES176834A1 (en) | 1943-04-07 | 1947-02-15 | IMPROVEMENTS IN ELECTRICAL SIGNALING CUTICAL SYSTEMS |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB558743A GB582177A (en) | 1943-04-07 | 1943-04-07 | Multiplex high frequency electrical pulse signalling systems |
Publications (1)
Publication Number | Publication Date |
---|---|
GB582177A true GB582177A (en) | 1946-11-07 |
Family
ID=9798913
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB558743A Expired GB582177A (en) | 1943-04-07 | 1943-04-07 | Multiplex high frequency electrical pulse signalling systems |
Country Status (2)
Country | Link |
---|---|
ES (1) | ES176834A1 (en) |
GB (1) | GB582177A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2632058A (en) * | 1946-03-22 | 1953-03-17 | Bell Telephone Labor Inc | Pulse code communication |
-
1943
- 1943-04-07 GB GB558743A patent/GB582177A/en not_active Expired
-
1947
- 1947-02-15 ES ES176834A patent/ES176834A1/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2632058A (en) * | 1946-03-22 | 1953-03-17 | Bell Telephone Labor Inc | Pulse code communication |
Also Published As
Publication number | Publication date |
---|---|
ES176834A1 (en) | 1947-03-16 |
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