| 摘要 |
733,638. Electronic counting - apparatus. STANDARD TELEPHONES & CABLES, Ltd. Oct. 9, 1952, No. 25324/52. Class 106(1). [Also in Group XL (c)] An electric counting chain comprises a single crystal triode CT1, CT2, &c. for each stage arranged to have two (" on " and " off ") states, means interconnecting each pair of consecutive crystal triodes whereby if the first is in its " on" state the second will be operated from its "off" to its " on " state in response to the next pulse over a common input PN and reactive means, such as condenser C2, for preventing the second crystal triode being switched to its "on'" state by thesame pulse that switched the first. As described, the " off " and "on" states correspond to low and high current flow and may be produced by applying negative and positive triggering potentials respectively to the emitter electrode E, the triggering being caused by a positive feed-back effect in the current gain portion of the characteristic of the crystal triode. In the circuit shown, the emitter of CT1 is so biased as to be triggered by the first narrow negative input pulse from PN applied in common to all the base electrodes B (a negative pulse applied to B being equivalent to a positive pulse at E), thus increasing the potential of its collector electrode C and of the emitter E of crystal triode CT2; CT2 similarly responds to the next input pulse and raises the emitter bias of CT3, and so on. The circuit may be operated also by long or variable length input pulses of either polarity applied at PS to the circuit including rectifier MR1. Various circuits are shown for obtaining an output pulse from a given stage comprising, e.g., a telephone-type relay or a transformer. In another counter (Fig. 6, not shown), the collector electrodes are coupled by condensers, so that on operation of a crystal triode the preceding crystal triode is triggered back to the " off " state, and the last crystal triode is coupled to the first to form a ring.
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