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:
Jul. 31, 2001
Filed:
Jun. 16, 1999
Applicant:
Inventors:
Shuuji Yamaguchi, Tokyo, JP;
Naoki Furuhashi, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 4/108 ;
U.S. Cl.
CPC ...
H01L 4/108 ;
Abstract
To provide a piezoelectric transformer drive method and a drive circuit which is capable of preventing breakdown of the piezoelectric transformer due to excessive oscillation on its activation and of obtaining a high efficiency. Controller controlling the load power to a constant value is provided. The controller is controlled in such a manner that the driving of the piezoelectric transformer is initiated at a frequency higher than the resonating frequency on its activation and thereafter the drive frequency is gradually lowered without passing through the resonating frequency of the piezoelectric transfer on its activation.