Operation of Thermionic Vacuum Tube Circuits

Given the static characteristic of grid current-grid potential, and plate current-plate potential, for any three element vacuum tube, the general exact equations for the output current when the tube is connected in circuits of any impedance whatsoever, and excited by any variable voltage, are here derived. The method of derivation is illustrated in the special case where resistances only are considered, and the adaptation of complex impedance to use in non-linear equations is shown. Approximations that are allowable in various practical applications are indicated, and the equations are applied in some detail to grid-leak detectors, and in brief to other types of detectors, modulators, amplifiers and oscillators. Certain repetitions of previous work are contained in these pages, as it is believed that the applications of the novel features introduced are illustrated thereby better than by a description dealing only with new material.