Patents Assigned to Malcolm T. Gilliland
  • Patent number: 4922161
    Abstract: An automatic braking and speed control for a device driven by an electric motor. A controller provides a pulsed output voltage having a pulse width dependent upon the load seen by the motor (16). When the drive pulses are present two diodes (52,54) and a transistor (66) serve to maintain a power transistor (56) in the off condition. When the controller is not providing drive pulses and the motor (16) is being turned by the momentum of the mechanical device or by some outside force, such as gravity, the motor (16) functions as a generator and turns on two transistors (56,67) so that two resistors (51a,51b) apply a load to the generator (16). This provides a braking action between the output pulses so that the net speed of the motor (16) and its associated mechanical device is more dependent upon the output pulses provided by the controller.
    Type: Grant
    Filed: March 31, 1989
    Date of Patent: May 1, 1990
    Assignee: Malcolm T. Gilliland
    Inventors: Malcolm T. Gilliland, Charles L. Warner, II