An Electronic Differential Analyzer
James S. Koehler · Journal of Applied Physics · 1948
An electrical device is designed which will solve ordinary, non-linear, non-homogeneous differential equations or the boundary value problems based on such differential equations. The device is based on the fact that the charge on the condenser in a series resonant circuit varies with the time in a manner described by a linear second-order differential equation. The desired variations of the coefficients with time are fed into the apparatus by using a variable voltage generator. This generator provides a small voltage which varies with time in accordance with any given curve. The variable voltage generator has been constructed and operates satisfactorily. The resulting solution is drawn by an oscillograph. The instrument is designed to furnish a solution which does not deviate from the true solution by more than four percent.