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:
Nov. 26, 2002
Filed:
Nov. 16, 1999
Taiheiyo Cement Corporation, Tokyo, JP;
Abstract
In a piezoelectric transformer control circuit, when a load ( ) is disconnected from a piezoelectric transformer ( ) and changes to an open state, an output detection voltage (Vdet) becomes higher than a reference voltage (Vref ), and the output from a voltage comparator ( ) goes “Low”. When the output of the piezoelectric transformer ( ) is short-circuited to GND, the output detection voltage (Vdet) abruptly drops to almost “0” and becomes lower than a reference voltage (Vref ). The output from a voltage comparator ( ) goes “Low”. A voltage-controlled oscillation circuit ( ) detects the signal “Low” to stop the generation of the oscillation signal to a driving circuit ( ) for driving the piezoelectric transformer ( ).