Analog logarithmic and antilogarithmic circuits using switching transistors
A. J. Schiewe, K. Chen · 1957
As the function of modern control and computer systems becomes more complex, there is an increasing need of electronic analog circuits which automatically perform the mathematical operations of taking the logarithm and antilogarithm. The logarithmic function may be desired in itself as in conversion of linear inputs into logarithmic values for scale compression in one-dimensional instrument indicators and recorders. On the other hand, it may be used in conjunction with the antilogarithmic function to obtain the operations of multiplication, division, and taking powers and roots.