Patent GB-818989-A (GB)
Title: Telegraph code converter
IPC: H03M5/00
Filed: 1955-12-23
Abstract: 818,989. Code telegraphy. COMMERCIAL CABLE CO. Dec. 23, 1955 [Dec. 29, 1954], No. 36881/55. Class 40 (3). In a telegraph code converter comprising means for storing information representative of the elements of a character in a first code, a counting system for producing information representative of the total number of all the elements representing the character, means for combining the stored information with the information derived from the counting system to produce an output representative of the character, and translating means for producing an associated output in a second code in response to the combining means, the counting system and the storage means are returned to their initial conditions after and as a result of the conversion of each character from the first code to the second code. In the arrangement shown for converting from signals in the cable code to the corresponding signals in the five-unit code, a dot or dash relay 1K, 2K operated by the incoming signals brings into operation a pulse generator 1A producing pulses timed with the elements as they are received and which are passed to a dot matrix 4. If the element is a dot the matrix 4 is conditioned so that the pulse is passed to a dot/dash storage bank 7 over the corresponding lead 21 ... 24 provided for the code elements up to the number of four, occurring in the cable code. The operation of the dot/dash storage bank 7 by the dots on the conductors 21 ... 24 controls relays 31K ... 34K to apply potentials and neutral conditions, indicated by + and Œ respectively, selectively on four pairs of output leads 25a, 25b, 26a, 26b ... 28a, 28b leading to a conversion matrix 6 to which pulses are also applied from the counting bank 5 and, from which a potential appears on one of the conductors L1 ... L28 corresponding to a letter or lower case character or function, or on one of the conductors L29, L30 allocated to the letters-shift and figures-shift signals. A timing circuit 1B operated in response to a letter space in the cable code passes a pulse over lead 59 to the conversion matrix 6 and after a short interval a pulse over lead 13 to reset the counting bank 5 and also the dot/dash storage bank 7. The impulse on a lead L1 .. L28, L29 or L30 together with the control pulse on the conductor 59, causes the 5-unit coupling matrix 8, including sets of discharge tubes, selectively connected to the leads L1- L30, to form corresponding code combinations on the conductors 60 ... 64 or 65 ... 69, and the condition of the shift storage circuit 11 operates a shift relay in the output relay bank so that the pulses on the corresponding set of conductors 60 ... 64 or 65 ... 69 are effective. The relays 41K ... 45K are reset by a control pulse to pass the appropriate code combination from the relay bank over conductors 70 ... 74 to a five-unit reperforator or storage unit also operated by the control pulse. The control pulses on leads 75, 76, 77 are shown as emanating from the circuit 1C, but are in effect derived from a portion of this circuit, controlled by the letterspace circuit 1B. The space between words in the cable code is detected by a timing circuit 1C which passes a pulse over conductor 79 to the output relay bank 6 which operates so that a pulse is passed over conductor 72 to form the code combination - - + - - denoting space in the five-unit code. The detailed operation of the various component parts of the system is described in connection with Figs. 3A, 3B ... 6A, 6B (not shown).