AC SIGNAL GENERATING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide an AC signal generating apparatus which generates an attenuation AC signal in a simple configuration. SOLUTION: The AC signal generating apparatus includes: a microcomputer which functions as a rectangular wave generating means for generating two rectangular waves of frequencies being different a little from each other; a bipolar differential amplification circuit which inputs two rectangular waves and outputs a difference obtained by subtracting the voltage value of one rectangular wave from the voltage value of the other rectangular wave; and a low-pass filter circuit which is constituted of an active filter circuit and outputs an AC signal. In the microcomputer, an initial phase difference between two rectangular waves is 180° and generation of rectangular waves is ended at a point of time when a phase difference between two rectangular waves becomes 0. A stable attenuation signal can be obtained without the need of any circuit for attenuation particularly and without being hardly affected by external components or the like. COPYRIGHT: (C)2011,JPO&INPIT