Patents by Inventor Charles L. Schwalm

Charles L. Schwalm has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Speed controller for mill drives and the like
    Patent number: 4556830
    Abstract: A speed controller for a mill drive has two control portions. The first control portion has a first speed of response for controlling mill speed during normal operation. The second control portion has a second speed of response, faster than the first speed of response, for controlling mill speed following abrupt changes in load torque. The first control portion has a reference speed input and this is compared with actual motor speed and the result gives a current reference signal. The current reference signal is compared with a signal representing actual current to derive an error signal used to control the supply of power to the motor. The second control portion multiplies the current reference signal with a signal representing flux to provide a signal representing a model of developed torque. This is compared with a signal representing a model of load torque and the difference integrated to provide a signal representing a model of motor speed.
    Type: Grant
    Filed: September 19, 1984
    Date of Patent: December 3, 1985
    Assignee: Canadian General Electric Company Limited
    Inventors: Charles L. Schwalm, Walter A. Hill