Cross-point matrix circuit for telephone system - has logic gates which are used for applying pulses to thyristors at cross-points

摘要

A circuit is used to energise and de-energise cross-points of a matrix interconnecting unit for automatic telephone system. The matrix has interconnection by thyristors and the circuit adapts the system to control by computer. A typical cross-point has two thyristors (20, 21). Each thyristor (20, 21) is in series by its anode-cathode circuit between an horizontal (a0, b0) and a vertical (a1, b1) of the matrix. The gates of the two thyristors (21, 22) are connected to two outputs of a control circuit (22). The inputs (25, 26) of the control circuit (22) are connected to logic gates (27, 28). The gates (27, 28) are connected to a computer. The thyristors (21, 22) are switched on or off by the application of a pulse from the gates (27, 28).