GB887591A - Improvements in or relating to pulse generators - Google Patents

Abstract

887,591. Transistor pulse shaping circuits. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. May 10, 1960 [May 25, 1959], No. 17714/59. Class 40(6). A pulse producing circuit comprises an avalanche transistor J1 with its emitter and collector connected to a switching means, e.g. a second transistor J2, the collector being connected by a capacitor Cl, such that the switching means closes upon the triggering of transistor Jl to produce an output across the load R2. Diodes Dl, D2 are provided to normally hold J1, J2 cut off, and application of a trigger pulse to J1 produces a pulse at the base of J2 (Fig. 2). In order to increase the rise time of the collector current -of J2, the capacitor C1 is provided to force the collector of J2 positive. After C1 has become discharged, J2 may be maintained in a bottomed condition by hold J1 conductive or by a further current supply to the base of J2. To vary the amplitude of the output pulse, the emitter of J2 may be taken to a variable positive potential instead of earth. In a modification, Fig. 3 (not shown), the single transistor J2 is replaced by a pair of complementary transistors, with the emitter of J1 connected to the base of the PNP, and the capacitor Cl connected to the base of the NPN. If wide pulses are not required, the switching may be provided by a bridge rectifier circuit, Fig. 4 (not shown).