Switch using bipolar transistors for use in analogue computing

In this paper, a transistor switch for use in analogue-computing circuits is described, and the essential steps in its design are given. The switch is then applied, in a feedback configuration, to produce a fast, accurate method of resetting the initial conditions of an integrating computing amplifier. An assessment of the steady-state errors is provided, and a detailed transient analysis leads to the prediction of reset transients for both transistor and valve operational amplifiers. These transients are confirmed experimentally. It is shown that the switch leads to a cheap and accurate way of resetting integrators, which will allow solid-state analogue machines to be operated repetitively at rates of over 1 kHz.