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:
Mar. 24, 1998
Filed:
Mar. 08, 1996
Yasuhei Shimada, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A high power source unit employing a piezoelectric transformer detects whether the output of the piezoelectric transformer reaches a predetermined value or not using a comparator. Subsequently, using a frequency scanning circuit, an oscillation frequency of a driving frequency control circuit is scanned across a resonance frequency of the piezoelectric transformer. During this frequency scanning, the efficiency of the piezoelectric transformer is detected by a efficiency calculating circuit to detect the frequency where the efficiency becomes maximum, by a most efficient frequency detecting circuit. By maintaining this frequency, the piezoelectric transformer may operate at the frequency at optimal efficiency.