Patents by Inventor Paul Gregory Cardinal

Paul Gregory Cardinal 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).

  • VARIABLE VOLTAGE LOAD TAP CHANGING TRANSFORMER
    Publication number: 20090200290
    Abstract: Power supply systems for subsurface heaters are described herein. The power supply system includes a variable voltage, load tap changing transformer. Systems and methods for supplying electrical power to subsurface heaters using the variable voltage transformers are also described herein.
    Type: Application
    Filed: October 13, 2008
    Publication date: August 13, 2009
    Inventors: Paul Gregory Cardinal, David Burns