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:
Jan. 29, 1991
Filed:
May. 08, 1990
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An AC power source apparatus to be used in an AC corona generator necessary for a de-electrification/separation process, which is one of electrographic image forming processes, or in a case where a low frequency AC power source is required, has a construction such that a high-frequency pulse, whose time ratio is modulated trapezoidally with time, is applied to switching elements connected in inverse-series across a primary winding of a transformer, an inductance element having a regenerative diode and a reset winding is inserted between an intermediate tap of the primary winding of the transformer and a DC power supply input terminal, and an LC filter is formed by stray capacitance of a secondary winding of the transformer, whereby a desired output waveform can be produced with a simple circuit construction. A trapezoidal wave used in the AC power source apparatus is generated by an amplitude-controlled trapezoidal wave generator which includes a wave-forming capacitor which is charged and discharged by two variable current sources under control of a timing circuit.