Patent GB-658948-A (GB)
Title: Improvements in or relating to electric signal storage and re-transmission circuits
Inventor: BRAY FREDERICK HARRY
IPC: H04Q1/50
Filed: 1949-11-16
Abstract: 658,948. Automatic exchange systems. STANDARD TELEPHONES & CABLES, Ltd. Nov. 16, 1949, No. 29310. [Class 40 (iv)] In a keysender, digits are set up on groups of static electrical switches and transferred automatically one after another as complements to a binary counter comprising pairs of static electrical switches, the digits then being counted out by the counter. Start key KST energizes relay ST to apply anode potential to the cold cathode storage tubes AT1-4, RT1-4, &c. and to the even tubes of a counting chain CRT1-8, a pulse network PN1 firing the even tubes of the counter. Depression of a digit key KO-9 applies positive potential from contact st2 to leads connected by rectifiers to the trigger electrodes of one or a combination of the storage tubes AT1-4, BT1-4, &c. according to a code, the potential being blocked by the rectifiers except in the case of the first set of storage tubes AT1-4, which receives a pulse from the point P1 in response to the operation of a sequential operation distributing circuit (not shown) actuated by depression of the first digit key. The related storage tubes fire, and in like manner the other digits are set up on subsequent groups of storage tubes. When storage is complete, depression of start send key KSS energizes DS to ionize all storage tubes in the group following that used for the last digit, if all groups have not been used. Release of key KSS energizes relay DSR, which restores the sequential operation distributing circuit (not shown) and connects anode potential to the odd tubes of the counter CRT1-8. DSR also releases DS to cause the distributing circuit to apply a positive pulse to point P1 to cause all inert tubes in the first storage group to fire and pass positive pulses to ionize the related odd tubes in the counting chain, which operates on the binary system so that the complement with respect to 16 of the digit is entered. Operation of counting chain. Ionization of an odd tube extinguishes the associated even tube. Transfer of any digit fires either CRT5 or CRT7 to cause pulse network PN2 to fire tube TRT and energize TR, which operates IG when impulse springs A open. IG operates IP, which via pulse network PN1 applies positive pulses to the first pair of tubes in the counter as pulses go out over contacts B, the counter responding in known manner until all even tubes are ionized, when CRT8 fires tube SZT to operate SZ. Relay IG then falls back to stop the impulses at ig2, and by means not shown actuates the sequential operation circuit so that the second digit is transferred and transmitted in similar manner. Release' of IG also applies positive potential over a time delay network to fire tube IDT so extinguishing tube SZT and releasing SZ. After the last digit is transmitted, an attempt to transmit a non-existent digit fails because neither CRT5 not CRT7 is ionized and release of SZ operates CL to light the finish send lamp, start key KST is released and the sender returns to normal. The invention may be applied to registers and may use thermistors, hard tube trigger circuits, cathode-ray tubes or transistons instead of the gas-filled tubes.