| 摘要 |
1,087,257. Comparators. INTERNATIONAL STANDARD ELECTRIC CORPORATION. April 23, 1965 [April 28, 1964 (3)], No. 17193/65. Heading G4M. In a magnetic core comparator, each of a set of cores represents a respective signification of one comparand. In Fig. one of a number of magnetic cores K1. . . Kn is set to represent one comparand, the other comparand being set up on relay contacts KU 1... KUL each of which connects an output winding L1 . . . LL threading a selection of cores either to earth or to a further winding SK which threads all the cores in the opposite sense. The other ends of the output windings pass to a diode OR gate. A positive-negative pulse is then used to reset the set core. If the two comparands are equal each output winding L1. . . LL either has a pulse induced in it cancelled by a pulse induced in the further winding SK or has no pulse induced in it and is earthed, but if the comparands are unequal, the OR gate will receive at least one pulse the polarity of which will depend on the direction of the inequality. The core arrangement may be a translator for use in automatic telephone exchanges and the comparator above used for checking its operation. Alternatively, the comparator may be used as a translator, the cores being switched in turn until equality is obtained with the relay contact settings. Fig. 3 (not shown) shows a modification (operating similarly) in which transistors replace the relay contacts. When conducting, they earth their respective output windings and backbias off diodes leading to the further winding. In Fig. 4 (not shown) the further winding is omitted but a pair of output windings is provided for each bit of one comparand, each core being threaded by one winding of each pair. Switches earth one winding of each pair and leave the other floating. The output windings feed an OR gate. In Fig. 5 (not shown), output windings leading to an OR gate thread selected cores of a first group and are connected in series with respective output windings threading cores of a nominally similar second group. Corresponding cores in the two groups are set and reset in such a way that output pulses from the two groups, produced on reset, cancel giving no output from the OR gate, unless a fault exists. The core groups may be translators in a telephone exchange system in which ease the translator outputs are used for call control only if they agree as above. The cores may be square-loop cores as above or may merely act as transformers. |
