GB682672A - Apparatus for generating complex electrical waveforms - Google Patents

Abstract

682,672. Thermionic distributers. TOULON, P. M. G. March 30, 1949 [March 30, 1948], No. 8593/49. Class 40 (iii). A number of complex alternating voltages, each with peaks displaced in phase from those of the other voltages, which voltages may be used for distributing the components of a signal in a multiplex telephone circuit over a number of subscriber's lines, are produced by adding together different combinations of voltages selected from alternating voltages of more than one frequency derived from oscillators, there being a number of phasedisplaced voltages at each frequency. Signals received at E are distributed over lines such as 2, 2<1>, 2<11> in which are rectifiers 3, 3<1>, 3<11> blocked by a common battery 4. Each line is unblocked in turn, to allow passage of a signal element, by the successive voltage peaks, e.g. 23C, 23<1>C, Fig. 3, of complex waves produced in the different lines by combinations of secondary windings, e.g. 19, 21; 19<1>, 20<1>, 21<1>, 22<1>; and 19<11>, 20<11>, 2111, 22<11> of transformers 14<1>, 15<1>, 17<1>, 18<1>. The primary windings 14, 15 are fed at the same frequency K1F from an oscillator 9 with a mutual phase displacement of 90 degrees produced by an arrangement comprising valves 13, 13<1> and the primary windings 17, 18 are fed from oscillator 10 at frequency K2F with a phase displacement of 90 degrees from valves 16, 16<1>. F is the frequency of repetition of the signals. Appropriate magnitudes and phasing of the voltage peaks are produced by selecting suitable numbers of turns and directions of connection, of the secondary windings of the transformers. The oscillators are kept in synchronism with the signals by pulses fed over line 8. A single generator may control more than one distribution circuit.