CHAPTER 7 - NON-LINEAR COMPUTING ELEMENTS

Abstract

This chapter reviews non-linear computing elements. Computing elements capable of performing operations other than adding, integrating, and differentiating are needed. The most important of these additional elements are multipliers, dividers, and generators of trigonometric and other analytic or arbitrary functions. Networks for the production of many discontinuous functions such as limiting and backlash devices, and trigger circuits, are also required. It is in the development of these elements that the analogue computer designer has needed to be at his most ingenious, and a large variety of methods have been proposed to perform these functions, some of which are wholly electronic, and some are electro-mechanical. All these devices are classified as non-linear computing elements. Multiplication is the most important of the non-linear operations, and many techniques, both electronic and electro-mechanical, have been proposed. Of the electronic methods, experience has indicated that two are outstandingly better than the rest. These are the “variable mark/space” multiplier, and the “quarter-squares” multiplier, both of which are described subsequently , although some attention is paid to the less successful devices also.