Rotation control device

摘要

In a rotation detection apparatus, a magnetism pattern section provided with plural magnetic poles and a FG (frequency generating) pattern section provided with plural toothed wire circuits are located so as to face each other. When either one of the magnetism pattern section and the FG pattern section is rotated together with a rotating member, plural wave signals are electrically induced in the plural toothed wire circuits. A signal processing cicuit synthesizes the plural wave signals so as to output a multiplication signal and detects the rotation of the rotating member based on the multiplication signal.