| 摘要 |
1284776 Cross-point switching matrices TELEFONAKTIEBOLAGET L M ERICSSON 7 Nov 1969 [8 Nov 1968] 54749/69 Heading H4K A matrix of diode pairs DB, DC, over which set and reset currents are applied to an array of bi-stable cross-point elements Z, such as polarized relays, are selected by operation of a column relay KR followed by operation of a row relay RR, driving current of a set polarity being applied by relay BR and of a reset polarity by relay CR, initial operation of a column relay KR establishing from resistors r1, r2, a reverse bias to the diode pairs or a column such that should one of the diodes of the column conduct excessively in reverse there will be a deviation in the potential of the row wire as coupled over the associated cross-point element Z and a detector B 1 which monitors the potential of each row of the matrix will signal the fault. Should a fault be signalled in response to operation of a column relay KR, subsequent operation of a row relay to select a cross-point is inhibited. In the detector B1, depending on whether a diode DB or a diode DC is at fault in the matrix, the deviation of row potential activates a transistor pair T3, T4 over diode D2, or a transistor pair T1, T2 over a diode D1. The distinction between the diodes is not, however, preserved as the fault outputs are effectively combined and gated out by a control pulse by means of gates A1, A2, A3. The resulting fault signals thus indicates a fault existing in the matrix. |
