Device and method for damping the movement of the armature of electromagnets

摘要

The armature of an electromagnet experiences increasing acceleration during its movement from the non-energised quiescent position into the limit position when the coil is excited. This results in it knocking hard against the end stop, this being associated with noise being produced and with vibration. The invention comprises a method and a device with whose aid the coil current of the magnet is influenced in such a manner that, as the air gap reduces, the armature speed is reduced when the coil is energised in such a manner that the armature lands on the end stop at a low speed, and the development of noise and vibration in consequence are avoided. In order to achieve this, a signal is produced which is proportional to the armature speed. A functional dependence, which is contained in this signal, on the current is corrected by division by the coil current. If a current control loop keeps the result of the division constant, then the armature speed is reduced as the air gap becomes smaller. The invention can be used with electromagnets of any desired physical shape.