| 摘要 |
1,140,750. Transistor amplifying and oscillating circuits; remote control of radio receivers. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 23 Aug., 1966 [26 Aug., 1965], No. 37642/66. Addition to 119,708. Headings H3Q and H3T. The parent Specification discloses a number of transistor circuits which can be adjusted to act as either high Q circuits or alternatively as oscillators: according to the present invention these are modified in that the two or more series-connected semi-conductor diodes are replaced by the emitter-collector path of an auxiliary transistor. Thus, in an arrangement comprising transistor T1 with its collector connected to the base of a second transistor T2, and with a phase-shifting loop comprising the network C, R2 connected between the emitters, the collector circuit of transistor T1 comprises the collector to emitter path of a further transistor T10. The base of further transistor T10 is connected to a tap on a voltage divider connected between its collector and emitter: as shown, the voltage divider comprises capacitors C11, C12 which together provide the phase-shift. ing circuit causing a phase-shift equal to but of opposite sign to that of the feedback network at the resonance frequency of the circuit. |
