| 摘要 |
700,239. Semi-conductor circuits for generating oscillations. WESTERN ELECTRIC CO., Inc. Dec. 23, 1949 [Dec. 29, 1948], No. 32974/49. Class 40 (6) An electric oscillation generator comprises a transistor arrangement in which α (the ratio of increments of collector current to increments of emitter current) exceeds unity, and a feedback path from the collector to the emitter, which includes in series an impedance element adapted to restrict the feedback to a desired frequency. Fig. 1 shows a transsistor circuit comprising a block of N- type semi-conductor 1, a base electrode 2, emitter 3 and collector electrode 4. A potential source 5 biases the collector electrode, and the bias for the emitter electrode is provided by resistances 6 and 7 as described in Specification 700,235. Positive feedback is provided by series resonant circuit 12, 11, connected between the collector and emitter electrodes, so that oscillations are produced which may be supplied to a load via transformer 13. Alternative arrangements are described in which the output is taken via an inductive coupling with inductance 12, or a piezoelectric crystal may be used in place of the condenser and inductance circuit 11, 12. Resistance 14, byepassed by condenser 15, prevents damage due to excessive direct current. Reference is made to Specifications 592,260, 592,303, 595,601, 632,942, 632,980 669,399, 694,021, 694,022, [Group XXXVI], 694,026, 700,232, 700,235 and 700,238 regarding the use and production of transistors. |
