| 摘要 |
<p>PURPOSE:To prevent the brake action in a regenerative current, by providing a control function acting so as to decrease the regenerative current to zero even if it is allowed to flow in an electric motor, when a handle is returned by self-aligning action. CONSTITUTION:An electric current is theoretically obtained when a motor is locked, and a voltage signal alpha¦Vc¦, obtained by multiplying a voltage conver sion value in this time alpha time by an absolute value amplifying circuit 19, and a voltage signal ¦V1¦, forming motor current equivalent voltage V1 to an absolute value by an absolute value circuit 18, are input to a comparator 17, When the compared result in the comparator 17 is in a relation where ¦V1¦<alpha¦Vc¦, the comparator 17 is inoperative maintaining a condition with a contact 15a open while 15b close of a switch 15 because the electric motor (m) is placed in no locked condition. When the result of the comparator 17 is in a relation where ¦V1¦>alpha¦Vc¦, the motor (m), in which a supplied current decreases to zero, generates no brake action because the switch 15 closes the contact 15a while opens the contact 15b.</p> |
