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:
Apr. 14, 1998
Filed:
Aug. 05, 1996
Toshiyuki Zaitsu, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a converter or inverter comprising a switching circuit (23) for switching a direct current input signal into an alternating current switched signal, a piezoelectric transformer (25) for driving a load (27) with a converter output signal, and an FM modulator (43-47) for detecting the converter output signal to produce a rectangular signal for adjusting a switched frequency of the switched signal, a duty ratio adjuster (49) is supplied with the direct current input signal to control the rectangular signal for adjustment of a duty ratio of the switched signal. Preferably, a filter (29) filters the switched signal for the piezoelectric transformer. The converter is given a high efficiency by use of a rectifier on producing the converter output signal. Furthermore, the switching circuit may comprise first (31) and second (33) switching elements, which may be used as an active clamp circuit to linearize a feed forward characteristic of the duty ratio.