| 摘要 |
PURPOSE:To drive a motor automatically again by alternately applying forward- rotation conduction and reverse-rotation conduction to the motor at every fixed time until the release of overload is detected when overload is detected. CONSTITUTION:A micro-computer 1 controls the direction of rotation of a motor 5 driving an air mixing door 7 in response to a deviation between an opening set value and an output from an opening detecting circuit 8. When the currents of the motor 5 detected by a current detecting circuit 6 are larger than a predetermined value, the state of overload is decided, and forward- rotation conduction and reverse-rotation conduction are conducted alternately to the motor 5 at every fixed time. When the state of overload is released and motor currents lower, the control of the motor 5 is reopened. When motor currents do not drop even when a set time passes, the conduction of the motor 5 is stopped. |
