| 摘要 |
753,953. Transistor generating circuits. PHILIPS ELECTRICAL INDUSTRIES, Ltd. July 28, 1954 [July 31, 1953], No. 22060/54. Class 40 (6). In an oscillator, the output - circuit of a transistor amplifier feeds the input over a transformer and bridge connection including a series resonant circuit and voltage variable resistor. The directly coupled transistor amplifier 1, 2, Fig. 1, feeds over transformer 4 a bridge comprising a series resonant circuit 6, a stabilizing lamp 7 and resistors 9, 10. Signals from the opposite diagonal of the bridge are fed to the base-emitter circuit of junction transistor 1. The working points of the transistors are stabilized by a common resistor 3. Transistor 2 is of the point contact type. In a modification, Fig. 2 (not shown), a tapped secondary is employed, returned to the join of biasing resistors 15, 16 and the series resonant circuit is connected in series with a resistor 7 having a negative temperature coefficient. The lead to the base of transistor 1 is taken from the junction of these two elements. Two oscillators may be employed to derive a difference frequency. |
