| 摘要 |
PURPOSE:To obtain a DC voltage corresponding to a speed without contact, by differentiating the terminal voltage of an AC speed detecting generator and discriminating its polarity to detect a position and rectifying the output of the AC speed detecting generator by this position detection signal. CONSTITUTION:Electromotive forces eU, eV, and eW induced in respective phase windings of a three-shase AC generator 10 are differentiated in a phase detecting circuit 14. Voltages eU+30 deg., eV+30 deg., and eW+30 deg. having phases earier than those of induced voltages eU, eV, and eW by 30 deg. are generated in a voltage synthesizing circuit 12 and are rectified by switching analogue switches S1-S3 by position detection signals eU', eV', and eW' obtained by differentiation and are synthesized in an inverting amplifier 18, thus obtaining a DC voltage eO proportional to the speed. |
