A multistable transistor circuit

Abstract

This paper explains a multistable circuit which appears to be well suited to transistor characteristics. This circuit utilizes those characteristics of junction transistors which are inherent in the device and do not require close control during manufacture. Desirable features of the circuit are that it can theoretically have any number of statically stable states and that these states may be achieved using only two transistors with alpha less than one or one transistor with alpha greater than one. Inherently, the circuit is able to count up or down with equal facility.The circuit achieves multistable states by controlling the feedback and hence the stability of the circuit. The amount of feedback in any circuit may be controlled by a number of parameters of the circuit. If one of these parameters is made to vary in a non-linear manner over the operating range of the circuit, and if certain other conditions are imposed, the circuit may be caused to have several regions of stable and unstable operating characteristics. Several means of varying the parameters of a circuit will be shown that will achieve the desired effect.This method of achieving multistable states is not limited to one particular circuit configuration. It is applicable, at least in theory, to nearly any system capable of supplying positive feedback. A number of practical circuits using this principle of operation will be given along with stability considerations for these circuits. In circuits of this type, a closer control is necessary on the energy of the triggering pulse than for more conventional circuits, eg., Eccles Jorden trigger circuits. Several methods which effectively achieve this control will be shown.-1 4 -