| 摘要 |
<p>The present invention relates to a method and an apparatus for reversing a piston rod in an injection device, the piston rod being operatively connected to a motor shaft of an electrical motor so that a rotational movement of the motor shaft is transformed to a translational movement of the piston rod, the piston rod being adapted to be moved between two end positions, the method comprising the steps of providing a first supply voltage level to the electrical motor, measuring sets of corresponding values of current provided to the motor and a corresponding position of the piston rod, and providing a second supply voltage level to the electrical motor when the measured position of the piston rod equals predetermined positions, the second supply voltage level having a RMS value being smaller than the RMS value of the first supply voltage level. The present invention further relates to an apparatus for carrying out the method.</p> |
