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:
Oct. 22, 2002
Filed:
Nov. 15, 2000
Lynn Schultz, Nashua, NH (US);
Peco II, Inc., Galion, OH (US);
Abstract
Current measurement apparatus and methods are disclosed to measure load DC output current on the secondary side of a high frequency transformer in a switched power supply. Current in the primary side of the transformer is detected with a current transformer, which produces a voltage across a resistance proportional to the primary current in the high frequency transformer. Averaging of the voltage across the resistance is performed during periods of power transfer in the high frequency transformer and held by a capacitor until the next period of power transfer. The held voltage is used to determine the true load DC output current on the secondary side of the high frequency transformer by the turns ratio relationship of the secondary current to the primary current of the high frequency transformer. By averaging the voltage only over the periods of power transfer in the transformer, the effects of magnetizing current in the high frequency transformer are negated, thereby affording a more accurate measurement of DC output current.