Electronic damping apparatus

Apparatus for controlling the movement of a movable element to bring said movable element to rest at a desired stopping position, said apparatus comprising:

• a multi-phase drive motor having a drive shaft coupled to said movable element for driving same, four electrically conductive coils mounted in position-displaced relationship about said shaft, and means coupled to said drive shaft and responsive to the selective energization of said coils by respective motor drive signals for causing the corresponding rotation of said drive shaft and movement of said movable element;
• a sensor coupled to said drive shaft and responsive to the rotation thereof for generating an electrical signal containing information indicative of the direction, speed and distance of movement of said movable element;
• means for detecting from the distance information indicated by said electrical signal whether said movable element is within a predetermined distance of said desired stopping position;
• and
• control means for controlling the levels of said motor drive signals in dependence upon the direction information indicated by said electrical signal following detection of said movable element being within said predetermined distance of said desired stopping position, said motor and thus said movable element being brought to a final stop with only a single one of said motor drive signals and thus corresponding single motor coil on, said control means including means for selectively turning on and off or reversing either the two coils displaced counterclockwise of said single motor coil about said shaft or the two coils displaced clockwise of said single motor coil about said shaft in dependence upon the direction information indicated by said electrical signal.