Analysis and Design of a Transistor Blocking Oscillator Including Inherent Nonlinearities

Abstract

An analysis of transistor blocking oscillators is presented which differs significantly from previous approaches in that the nonlinear dependence of collector current and base voltage upon base current is considered. First, the nonlinear differential equations governing circuit performance are derived considering the effects of alpha cutoff, collector capacitance and leakage and magnetizing inductance. The relative importance of the various terms in this equation during transition, relaxation and recovery intervals is discussed from a physical viewpoint. Analog and digital computer solutions of the nonlinear differential equation yield pulse responses which give excellent agreement with experimental results for various signals, transistor characteristics and values of passive circuit elements. The paper concludes with a design example in which the analysis is confirmed by experiment.