| 摘要 |
PURPOSE:To surely detect the rotational speed and a direction by making the resistance value of a brush for detection such one that the value of a first current in an armature coil when the gap between armatures is stopped with a brush for detection and the value of a second current before and after the stopping fulfills the specified rate. CONSTITUTION:The resistance value along the gap between the armatures of brushes BA and BB for detection is such one that the value of the current I1 in a connected armature coil when the gap between armatures CPM1-COM3 is stopped with a brush BA or BB for detection and the value of the current I2 before and after the coupling fulfills 0.8 I1=I1. In the position right before the rotational position of a motor reaching 100 deg., at the right position, and the position immediately after it, armature coils L1 and L2 in series and an armature coil L2 are parallel, and at the position right before it, the potential at the point a is E0, and the potential at the point b is 0/2, and the potential at the point c is 0, and at the right position, it is short-circuited, and even at the position right after it, the magnitude and the direction of the current does not vary from the one right before it. |
