Driving apparatus for cross-coil type analog indicating instrument

摘要

A pulse signal generated by a car speed sensor is converted to an analog voltage by a F-V converter, and two sawtooth signals are formed by two sawtooth current generators based on the analog voltage. The sawtooth currents are then converted into two triangular wave voltages by two I-V converters. Three-stage function generators change the slope of each of the triangular wave voltages step by step and form an approximated sine wave voltage and an approximated cosine wave voltage. A zero-cross compensating circuit is provided in each of the first stage function generators and adjust the triangular voltage to cross zero point.