Anordning vid flerkanal-pulskommunikationsanläggningar

摘要

916,393. Automatic exchange systems. TELEFONAKTIEBOLAGET L. M. ERICSSON. March 14, 1960 [March 13, 1959], No. 8940/60. Addition to 836,756. Class 40 (4). In a resonant transfer system in which a normal connection between subscribers involves the pulse interconnection of a plurality of highways in tandem, resonances of the type described in the parent Specification, to ensure discharge of the highways at the end of the pulse period, are arranged not only for normal connections but also for other connections such as tone signals, or operator's intrusion which involve a different number of highways. As shown a normal connection is established between subscribers Ab1, Ab2 via primary highways Tp1, Tp2 and secondary highways Ts1 Ts2 by pulsing contacts Ka1, Ka2, Kps1, Kps2 and Kss, so interchanging the charges on the capacitors C. Tone signals may be applied to circuit L1, C1 connected by contacts Ki to Tpl. In the event of the tone signal being of the intermittent kind, the interruptions may be effected by failure to pulse contacts Ki during these periods. The values of the capacities Cp and Cs are therefore chosen in such a way that the highways are in the discharged state at the end of the pulse period in .all of the following cases: (a) Subscriber Ab1 connected to highway tp1 alone. (b) Subscriber Ab1 connected to tone signal source Sign via Tp1. (c) Subscriber Ab1 connected to subscriber Ab2 via Tp1, Ts1 Ts2, Tp2. This is achieved by adjusting the constants so that the resonant frequencies of the circuits involved are various multiples of the L, C circuit resonance frequency. If it is required for Cp to be larger than Cs (because of the capacities of the large number of Ka switches) it is shown that this can be arranged by using a larger value of C1 (and consequently a smaller value of L1). Provision for operator intrusion by means of a circuit L11, C11, Fig. 2 (not shown), connected by a pulsed contact to Ts2 is also made. Here again C11 has to be larger than C and L11 smaller than L. Mathematical formulµ are provided.