| 摘要 |
A drive unit (3) and a method for controlling a control valve element(5). The drive unit comprises an electric motor (10) comprising a drive shaft (16) adapted to be connected to a control shaft (7) of the control valve element and rotated between a first and a second position. The drive unit com- prises a gear box (12) and a control unit (14) adapted to rotate the drive shaft to positions between the first and second position. The electric motor, the gear box and the control unit are combined in a single mechatronic unit (15). The electric motor is of a type configured to allow rotation of the drive shaft a number of revolutions. The drive unit comprises a detector (32) adapted, at startup of the drive unit, to detect a position of the drive shaft relating to the first or second position of the drive shaft. The control unit is adapted to determine the first and second position of the drive shaft based on the detected position. |
