The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 22, 2010
Filed:
Nov. 16, 2007
Donald J. Lucas, Stoneham, MA (US);
Donald J. Lucas, Stoneham, MA (US);
Azure Dynamics, Inc., Woburn, MA (US);
Abstract
An RFI/EMI filter for a variable frequency motor drive system includes a variable frequency drive; a common mode choke; a motor; a cable including a plurality of power leads interconnecting the motor with the variable frequency drive and passing through the choke; a ground shield surrounding the cable and connected to motor ground and variable frequency drive ground; and a common mode return conductor interconnected between the variable frequency drive and the motor and disposed within the shield and passing through the choke for returning a portion of the common mode current to cancel a portion of the saturation current experienced by the choke to increase the portion of the common mode current carried by the return conductor and decrease the portion carried by the shield to reduce the RFI/EMI contributed by the shield.