Ternary Logic in a Positional Control System

The application of COS/MOS integrated circuits in the construction of a three-valued positional control system is presented. A unit-distance ternary code and the design of a ternary encoder are given. A ternary code converter able to translate this unit-distance code to the signed ternary code is described. A ternary threshold level detector is required to convert a noisy, slowly-changing, analog voltage into an abrupt digital logic change at required threshold levels. A three-valued comparator is constructed to compare the reference signal with the one fed back, and to supply an error signal. The logic design of the ternary control circuit is also presented.