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. 22, 2011
Filed:
Apr. 23, 2008
Kengo Kimura, Niiza, JP;
Kengo Kimura, Niiza, JP;
Sanken Electric Co., Ltd., Niiza-shi, JP;
Abstract
An AC conversion circuit includes a main transformer having a primary winding and a secondary winding to electrically insulate the AC power source side and the discharge tube side from each other, an ICarranged on the AC power source side, a plurality of switching elements arranged on the AC power source side and driven by the IC, to pass a current through the primary winding of the main transformer based on the DC power, an ICarranged on the discharge tube side, to generate a pair of rectangular-wave signals for conducting PWM control on a current passing through the discharge tube and having the same pulse width with a duty ratio of less than 50% and a phase difference of about 180 degrees, and one or more signal transfer insulated elements to send the pair of rectangular-wave signals from the ICto the IC. The ICdrives the plurality of switching elements according to the pair of rectangular-wave signals from the one or more signal transfer insulated elements, so that positive-negative symmetrical AC power is supplied from the secondary winding of the main transformer to the discharge tube.