| 摘要 |
PURPOSE:To obtain an increased driving torque for moving a door glass unit upward directly from a DC motor by changing the position of a brush in sliding contact with the commutator of the DC motor on moving the door glass unit upward and downward. CONSTITUTION:When change-over switches 2 and 3 are closed on the moving- down position a side, then a diode D1 is biased in the forward direction, and by feed with a first brush 5 and a second brush 6, a DC motor 8 is rotationally driven. When the change-over switches 2 and 3 are changed over to a moving- upward position b, then a diode D2 is biased in the forward direction, and by the first brush 5 and a third brush 7, current is fed to the DC motor 8. When the change-over switches 2 and 3 are changed over to the moving-upward position b, then current is fed by the first brush 5 and the third brush 7 which is shifted positionally by a specified angle theta from a proper current distributing position, and so by the positionally shifted degree of the third brush 7, armature- internal resistance is reduced, and according to the reduction, armature current is increased. |
