The use of silicon diodes in d.c. modulators and their applications to drift correctors for computing amplifiers

The basic computing element of an electronic analogue computer is the high-gain d.c. amplifier, but in order to overcome its inherent drift some form of auxiliary drift-correcting amplifier is frequently used. The paper describes a silicon diode modulator for use in such drift correctors, and shows that the zero stability which can be achieved is comparable with that given by the conventional relay modulator. It is also shown that the use of the diode circuit results in a number of improvements in the overall drift-corrector performance, such as a higher frequency response and practically unlimited life; the design of such a drift corrector for use with a given d.c. amplifier is described in detail and the resulting performance is assessed.