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. 06, 2001
Filed:
Aug. 05, 1999
Taiheiyo Cement Corporation, Tokyo, JP;
Abstract
When an input voltage rises, (the amplitude of) a sine-wave voltage for driving a piezoelectric transformer (,) increases, so that a detection voltage (Vti) rectified by a rectifying circuit (,) also increases. An output voltage from an error amplifier (,) for comparing the detection voltage (Vti) with a reference voltage (Vref,) rises. If the output voltage from the error amplifier (,) rises, a voltage-controlled oscillation circuit (,) decreases the duty ratio of an oscillation signal to be output. In a driving circuit (,), as the duty ratio of the oscillation signal decreases, the amplitude of a fundamental wave contained in a rectangular wave to be output decreases to be a small driving voltage to the piezoelectric transformer (,).