| 摘要 |
692,802. Semi-conductor devices. STANDARD TELEPHONES & CABLES, Ltd. Aug. 17, 1951 [Aug. 25, 1950], No. 21041/50. Class 37. [Also in Group XL (c)] An electric trigger circuit comprises a crystal triode conditioned such that collector-current, emitter-current curve is of the hysteresis type, means for biasing the emitter electrode such that the collector current has two possible values, and means for applying a trigger pulse to the emitter to switch the collector current from one possible value to the other. Fig. 1 shows how the collector current rises suddenly at point 12 as the emitter current is increased, and falls suddenly at point 7 as the emitter current is decreased. In Fig. 2, the emitter 16 is biased to a level corresponding to point 9 in Fig. 1, and the collector current is switched between the two values indicated at 10 and 11 in Fig. 1 by means of positive and negative pulses which are applied to the emitter through transformer 19. Output pulses are taken from the collector 17 between terminals 24 and 25. An additional control electrode 18 may be provided as described in Specification 681,829, [Group XL (c)], which is spaced between 0.005 and 0.015 inches from the other electrodes, and is biased in the forward direction whereby the hysteresis effect may be controlled. The rectifying contacts may consist of small areas of metal film as described in Specification 686,915. In plating these electrodes on N-type germanium, the germanium surface should be etched with an alkaline solution and then plated from an alkaline copper-plating solution containing a small quantity of arsenic which serves as a donor impurity. Reference is made to Specification 681,809, [Group XXXIX], regarding electroforming treatment.
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