Patent GB-753002-A (GB)
Title: Improvements in or relating to register-senders for use in telephone systems
Inventor: DENBY JAMES FREDERICK
IPC: H04Q1/32
Filed: 1954-11-06
Abstract: 753,002. Automatic exchange systems. AUTOMATIC TELEPHONE & ELECTRIC CO., Ltd. Nov. 6, 1954, No. 32179/54. Class 40 (4). A pre-transmission pulse is applied to the counting circuit of a register-sender and the corresponding impulse to line is suppressed, the pre-transmission pulse testing whether or not a digit has been injected into the counting circuit. If so, impulses are sent to line until the counting circuit is restored to zero and a further impulse is sent to compensate for the pre-transmission pulse. A common translator serves several registers. The counting circuit and impulse sender are shown in Fig. 1, the associated control circuit in Figs. 2 and 3. The storage circuits are not shown but are each associated with a display element DE comprising four tubes arranged on the binary principle, the display elements being effective sequentially to inject the corresponding digit into the left-hand side of the counting circuit. When the register is taken into use relay B (not shown) operates to connect H.T. to lead SHT and a start pulse is applied to lead ST. Tubes RA, RB, ZA, ZB, RJA, RLA, BCB, BEB, BGB, BJB strike and relay SZ energizes to short-circuit the loop impulsing springs, Fig. 1. When the translator has determined the routing digits application of a display pulse to lead DP causes the first routing digit to be entered in binary form on tubes WD, XD, YD, ZD. All the tubes of each stage of the counter, say WD, BD, BCA, BCB, have a common anode resistor so that when a tube of one pair, say WB, BD, is struck the conducting tube of the other pair BCA, BCB is extinguished. According to whether one of the left-hand or right-hand pair is conducting so the particular stage of the counter is said to be in left-hand or right-hand condition. Each stage also includes a pulse-repeating tube such as PRD primed from the right-hand pair of tubes. When PRD fires it repeats the pulse to BD and also to the next stage. Counting out routing digit. Relay D operates to a loop on the outgoing route and energizes relay IG at the next opening of springs MAG which now control relay IMP. Each operation of IMP extinguishes tubes ZA, ZB, RA and strikes OG to pulse the first stage of the counter circuit. Impulses are meanwhile sent to line by the loop springs in anti-phase to the springs MAG, the first opening of the loop springs being ineffective because tube RJA is conducting at that time so that relay SZ is energized. If the first stage of the counter is in right-hand position so that BCB is conducting then PRD strikes to extinguish BCB, fire BD and apply a pulse to the next stage. If, however, the first stage is in left-hand position so that WD is conducting then BCA strikes to extinguish WD. PRD not being primed does not strike. Each stage operates in the same manner, the digit being entered originally on tubes WD, XD, YD, ZD and BCB, BEB, BGB, BJB, and the counting being effected by tubes BD, BF, BH, BK and BCA, BEA, BGA, BJA, with tubes PRD, PRF, PRH, PRK effecting transfer. Each release of IMP extinguishes OG and any of tubes PRD-PRK which are conducting. The first release of IMP also strikes RD and RF to energize ST to improve the impulsing characteristic of the loop and release D. RD also strikes RH to extinguish RJA to restore relay SZ to remove the shunt from the loop springs so that impulses after the first are sent to line. The counting circuit and impulse sender continue to function in this manner until all the stages of the counter assume right-hand position. As the first pulse to the counter had no corresponding impulse to line, however, the apparatus continues for one more step. The extra pulse strikes all the pulse repeaters PRD, PRF, PRH, PRK to set all stages to left-hand position, PRK signalling the control circuit to end transmission by striking OA. OA fires OB to strike RC, OH, OX. OH pulses lead RIP to initiate the timing of the interdigital pause. Interdigital pause. This pause can be adjusted in steps of 100 msecs. from 200 to 1700 msecs. by variably strapping terminals RIP and DV to terminals RW-RZ of the counting circuit, representing 100, 200, 400 and 800 msecs. respectively. When OH pulses lead RIP the appropriate digit is injected into the counting circuit from the right-hand side. The last impulse to line and the additional pulse to the counter are sent and relay IMP restores to extinguish the pulse repeater tubes together with OA, OB, OG, OH. It also strikes RA and RB. As RC is already conducting, RE also fires to strike RJ and operate SZ, which shortcircuits the loop springs to prevent transmission to line. Tube OG again follows relay IMP to pulse the counting circuit as before until all the pulse repeating tubes PRD-PRK strike to fire OA and OB. As SZ is operated, OB this time strikes OH, OC, RC and RK to restore the counting circuit to right-hand condition ready to receive the next routing digit. Routing digit display counter DCR. When the register is first taken into use a pulse on lead SA, Fig. 3, strikes DA which primes a tube PRA for the second routing digit. Consequently, when OC fires, OE and OF respond to strike the PRA tube to pulse the DA tube for the third digit. The PRA tube also pulses the tubes of the second routing digit store to inject this digit into the counter circuit. Release of IMP extinguishes tubes OA-OJ and the pulse repeating tubes, RA, RB, RE strike to extinguish RC. The next operation of IMP applies the pre-transmission pulse to the counter as described earlier, the loop springs being shunted. The PRA tubes in the routing digit display counter strike in turn for successive digits. The counter provides for a maximum of six digits but can deal with a lesser number. Following transmission of the last routing digit, say the fourth, when all stages of the counting circuit CC are transposed to left-hand position, PRK strikes OA followed by OB to fire RK, RC, OC, OH, and therefore OJ, OE, OF. OJ, OH transpose the counting circuit to right-hand position. OF strikes PRA for the fifth digit. RK strikes RL. No digit is stored in the fifth routing digit store and so none of the tubes WD, XD, YD, ZD strikes and the counting circuit remains in right-hand position. When IMP next releases the PRA tube for the fifth digit extinguishes. At the next operation of IMP the counting circuit is transposed to lefthand position and PRK strikes OF, OH, OJ to transpose it back to right-hand position. Since RL has not extinguished, this second firing in one interdigital pause of RK strikes DNB primed by RL. Sending numerical digits. DNB primes PRN which strikes when pulsed by OF to pulse lead DCN, so causing injection of the first numerical digit into the counting circuit. The next release of IMP at the end of the interdigital pause causes RX and RZ to fire to extinguish RF and release ST. This opens the shortcircuit round D and restores IG. When the distant exchange is ready to receive numerical digits relay D operates to re-energize IG and the numerical digits are sent in the same manner as were the routing digits with the exception that at the end of each digit OX fires OZ, primed by DNB, to advance the numerical digit counter while PRN injects the next digit into the counter circuit. At the end of the last digit, relay B (not shown) releases to restore the register to normal. Prevention of sending overtaking registration. If sending catches up with registration of numerical digits there is no digit in the next display element and the counting circuit CC remains or assumes right-hand position so that PRK and PRN strike repeatedly until the next numerical digit is received.