The use of analogue computers for solving linear differential equations

Abstract

An analogue computer is a device suitable for the construction of analogues upon which accurate measurements can be made. This definition covers a wide range of instruments such as network analysers, slide rulers, flight simulators and many- others. The majority of such instruments can only be applied to a very limited range of problems, and may be classed as Special Purpose computers. The only types of analogue computer which can be applied to a wide range of problems are the Differential analyser and the Electronic Analogue Computer: these general purpose computers have to be of more complicated design than special purpose machines, and consist of a number of separate units which can be interconnected so as to build up any required analogue. The Differential Analyser is based upon the use of mechanical adders and integrators, but normally uses electrical drive motors. The computing elements are built up into a complicated mechanical linkage such that the only motion possible is constrained to be that defined by the equations being examined. The Differential Analyser has the highest accuracy of all analogue computers, and its ability to integrate with respect to more than one independent variable allows very convenient methods of multiplication and function generation to be used.