GB1266886A - - Google Patents

Abstract

1,266,886. Transistor amplifying circuits. MICRO CONSULTANTS Ltd. 20 Oct., 1969 [3 Oct., 1968], No. 46912/68. Heading H3T. [Also in Division G3] An arrangement used as a constant current device comprises a transistor TR1, Fig. 1, with its collector connected to a load circuit and its emitter to a resistor R1, its base being connected to the output 4 of a differential amplifier 1. Negative feedback is provided between resistor R1 and the out-of-phase input 2 of the differential amplifier 1, the in-phase input 3 of which is connected to an input source V 1 . In a modification, transistor TR5, Fig. 2, is similarly connected, but a resistor R6 is interposed between its collector and the load: a further transistor TR6 is provided with its base and collector respectively connected to the collector and emitter of transistor TR5 and its emitter connected to the load. The Specification also discloses a modification of the arrangement of Fig. 1, in which a plurality of further transistors are provided with their bases connected to the base of transistor TR1, each having its own emitter circuit resistor and the collector feeding a constant current to a further load (Fig. 3, not shown). A corresponding modification of the arrangement of Fig. 2 is also disclosed (Fig. 4, not shown).