Logarithmic VU meter driver

Abstract

This paper deals with a construction and practical testing of a VU meter driver that includes an accurate rectifier and logarithmic driver of a pointer-type gauge. The logarithm is taken from the rectified signal by employing a capacitor discharge voltage curve. In the first step, a simple rectifier and logarithmiser was designed and built in order to proof the theoretical premises. Then, based on the experience with this circuit, the more complex design of the VU meter driver was created.