Patent GB-434300-A (GB)
Title: Improvements relating to electric remote control systems such as automatic telephonesystems
IPC: H02J13/00
Filed: 1934-06-21
Abstract: 434,300. Automatic exchange systems. SIEMENS BROS. & CO., Ltd., Caxton House, Tothill Street, Westminster, HUMPHRIES, H. E., 61, Rochester Way, Blackheath, London, and EDWARDS, H. J., 5, Summerhill Road, Dartford, Kent. June 21, 1934, No. 18373. [Class 40 (iv)] [See also Group XXXVIII] In a system in which control is exercised by current impulses as for example in automatic exchange systems, further signals are given by fleetingly opening the impulse circuit during the spaces between impulses or closing it during the impulses themselves or both. In one arrangement, off-normal springs on an impulse dial charge a condenser through a relay which thus fleetingly interrupts the impulse circuit. Selector control circuit, Fig. 3, modified to respond to fleeting impulses. All impulses are repeated by a high - speed relay S, which may be of the type described in Specification 405,436, [Group XXXVII], and when the circuit is seized this relay energizes a relay A for repeating impulses of ordinary duration to the driving magnet DM, a release relay B and a dialling relay C. Each relapse of S energizes a high-speed relay P and a fleeting relapse of S while A is energized causes PB, PA to pull up in succession. PA cuts off, PB and locks up. As a result the back contact of S is extended over wire W to a similar group of relays P, PA, PB (not shown). Similar arrangements responsive to fleeting operations of S with A de-energized might be connected to the front contact of S. Register controller for sending three digits at once, Fig. 5. When the register-controller is ready to send, SS (not shown), connects up the pick-up relay 1g which pulls up at the next opening of cc4b, arranges for the stepping of the sending switch and connects up the loop-springs in place of a direct connection through contact x. Springs cc3 send impulses of the usual type, springs cc1 send a fleeting break in each of the make periods between normal impulses and springs cc2 send a fleeting make in the break period constituting each normal impulse. The number of fleeting impulses to be effective is determined by relays TA, TB which respectively shortcircuit and disconnect springs cc1, cc2 at points determined by the markings of the hundreds and tens registers, H, T. If the units digit is greater than each of the others it is terminated by CO which is operated by TC when the sending switch is on the terminals marked over the lower bank U2 of the units register and the interrupter changes over to send the last units impulse over the loop If however one of the other digits is larger than the units digit, TC is operated over tb2 and the wiper U2 or over ta2 and the wiper U1 which marks a terminal in S3 one later than that marked in S4 by U2. In the latter case the operation takes place when the loop springs close at the termination of the last units impulse. The effect of the operation of TC in these circumstances is to cause a fleeting " make " at tc2 in addition to that produced at cc2 or a fleeting break at tc1 in addition to that given by cc1. This double signal indicates to the receiving apparatus the termination of the units digit. Alternatively the first ten normal impulses may be employed simply as carriers, the units digit being sent subsequently. Receiving circuit, Fig. 4 responsive to three digits at once. A high speed relay S (not shown), is included in the line circuit and operates A, B, C initially. Impulses of normal duration are repeated by A to the magnet SDM. Fleeting make signals are repeated by a high-speed relay P to relays QM, QQM which control magnet MDM and fleeting breaks are similarly repeated by PP to QB, QQB which control magnet BDM. If two fleeting breaks occur in one normal make interval or two fleeting makes occur in a normal impulse, high-speed relay CA is operated and energizes CB which remains locked and prevents any further action by normal impulses on magnet SDM. Rectifiers. Rectifiers R, Fig. 3 and R1, R2, Fig. 4, are provided to ensure that the release times of the relays are not affected by the circuits.