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:
May. 05, 2009
Filed:
Apr. 25, 2005
Applicants:
Norbert Huber, Teisendorf, DE;
Simon Graf, Burgkirchen, DE;
Inventors:
Norbert Huber, Teisendorf, DE;
Simon Graf, Burgkirchen, DE;
Assignee:
Dr. Johannes Heidenhain GmbH, Traunreut, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
The voltage of the intermediate circuit of a frequency converter is monitored, while the intermediate circuit is charged via charging resistors. When the voltage has not reached at least a reference voltage during a specific time constant, the charging process is interrupted prematurely. The reference voltage is selected to be considerably lower than the operating voltage of the intermediate circuit. The reference voltage may be less than half of the operating voltage of the intermediate circuit.