Simple Transistorized Logarithmic Time Base

Abstract

A time base is described which allows the spot of a cathode ray tube to be deflected at a rate proportional to the logarithm of the time. The circuit requires the use of two transistors, one of which serves as a conversion stage and the other as an amplifier stage. Two different sets of component values are given to cover a range of either two or three decades. The performance of the time base and its limitations in respect to temperature variations and supply voltage fluctuations are discussed.