GB898504A - Improvements in or relating to transistor switching circuits - Google Patents

Abstract

898,504. Transistor switching circuits. NATIONAL RESEARCH DEVELOPMENT CORPORATION. June 21, 1960 [April 3, 1959], No. 11368/59. Class 40(6). A switching circuit including a transistor, a driving transistor controlling the switching transistor, and a second driving transistor connected immediately to the base of the switching transistor such that the emitter-collector path of the second driving transistor may be rendered fully conducting to give substantially zero impedance between the base of the switching transistor when cut off and a bias source. A switching circuit for a magnetic core comprises two transistors Q1, Q2 having their emitter-collector paths in series, the collector of Q2 being directly connected to the base of a third transistor Q3 which has the magnetic core connected as its collector load between terminals A3, A4. Antiphase switching signals applied to terminals A1, A2 cause transistor Q3 to switch whilst maintaining a low impedance path in the base circuit. In an alternative embodiment Fig. 1 (not shown), the transistor A3 is replaced by eight transistors in a series-parallel arrangement.