GB1341302A - Logic circuits - Google Patents

Abstract

1341302 Code conversions COMPAGNIE INDUSTRIELLE DES TELECOMMUNICATIONS CIT-ALCATEL 3 Aug 1971 [3 Aug 1970 21 Oct 1970] 36397/71 Heading G4H [Also in Division H3] A transcoder Fig. 5 has 30 logic circuits P1- P30 in which each logic circuit has two seriesconnected thyristors A1, B1 the first input e 1 being connected to the anode of the first, and the other inputs e 2 , e 3 being coupled to the gates. Capacitors are provided at the inputs to prevent spurious triggering of the thyristors. In the transcoder of Fig. 5 each logic circuit receives three inputs selected from eight pulse receiving positions E 0 -E c , a unique logic circuit producing an output for each different three-out-of eight coded signal received at E 0 -E c . Each logic circuit output is connected by a unique diode arrangement to a selection of five possible output terminals S1-S16 to give a binary coded signal, corresponding to the received input signal. Relays at S1-S16, to operate a mechanical logic system, are thus able to be driven directly by the logic circuits by virtue of the use of thyristors. An alternative transcoder (Fig. 6, not shown) changes a two-out-of-five code into a binary code.