Patents Assigned to Tedeco AG
  • Control system
    Patent number: 3943973
    Abstract: A control system for remote proportional positioning of hydraulic directional control valves includes pulse duration modulation control of electrohydraulic converters controlling hydraulic valve spool positioners. Pulse groups supplied to the converters have a repetition rate of the order of 50 Hz to cause mechanical vibrations in the hydraulic liquid and the valve positioners, thereby reducing frictional hysteresis.
    Type: Grant
    Filed: March 21, 1975
    Date of Patent: March 16, 1976
    Assignee: Tedeco AG
    Inventor: Ted Zettergren