| 摘要 |
The matrix switch comprises a plurality of input lines (Y1-Y4), a plurality of output lines (Y1-Y4) and a plurality of crosspoint switches for selectively connecting one or more input lines to one or more output lines. When such a matrix switch is used for telephony systems the input lines are connected to the subscriber's lines and the output lines to the outgoing lines. Each of the input lines is coupled to input lines of an additional matrix switch via an impedance (which is equal to the characteristic impedance of the subscriber's line). The additional matrix switch has a first output line, which is connected via cross-point switches to the input lines of the additional matrix switch for terminating the selected input lines of the matrix switch with the impedance. A second output lines connects a tone generator to the input lines via the crosspoint switches. A further embodiment shows a matrix switch arranged for use with balanced lines.
|
