Patents Assigned to Performance Conrols, Inc.
  • Patent number: 5629616
    Abstract: A circuit accurately measures the current flowing in a load which is powered by a pulse-width modulated (PWM) arrangement. The current measurement circuit is transformer-coupled to the load. A first flux cancellation device produces a voltage which tends to reduce the flux in the transformer core to zero. A pair of peak detection circuits determine maximum and minimum voltages at the output of the first flux cancellation device, and another circuit measures the difference between the maximum and minimum voltages. This difference is a voltage which is proportional to the current flowing in the load. A second flux cancellation device includes an integrator which integrates the outputs of the peak detection circuits, and the output of the integrator is fed back to the first flux cancellation device.
    Type: Grant
    Filed: July 13, 1995
    Date of Patent: May 13, 1997
    Assignee: Performance Conrols, Inc.
    Inventor: Craig R. Weggel