Patents Assigned to Tycor International Corp.
  • Patent number: 5784236
    Abstract: The invention provides a circuit to protect an AC motor powered by a Variable Frequency Drive (VFD) from overvoltages caused by reflected waves. A full wave bridge rectifier circuit across the lines of the motor to be protected provides rectified voltage output to a capacitor, across which a low resistance discharge resistor in series with one or more zener diodes is attached. When an overvoltage above the clamping voltage of the zener diode(s) occurs across the protected lines, the zener diode(s) will conduct, causing the excess charge across the capacitor to discharge through the resistor until the voltage drops below the clamping voltage of the diode(s).
    Type: Grant
    Filed: May 22, 1997
    Date of Patent: July 21, 1998
    Assignee: Tycor International Corp.
    Inventors: Dale Tardiff, James Funke