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. 29, 1997
Filed:
May. 10, 1995
Hirofumi Nakata, Nara-ken, JP;
Hirokazu Kodama, Gose, JP;
Tsukasa Takebayashi, Yamatotakada, JP;
Satoru Fujii, Nara-ken, JP;
Kozo Hiyoshi, Amagasaki, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A pulse train pulse-width modulated by PWM control using a sine-wave signal and a carrier signal is inverted alternately in positive-negative polarity. With a high-frequency AC signal obtained by the inversion, a primary side of a transformer for insulating input and output from each other is excited. This arrangement makes it possible to employ a high-frequency transformer which has a capacity ratio of about 1/30 and a weight ratio of about 1/20 relative to a commercial-frequency transformer, instead of using it. Thus, an inverter apparatus can be reduced in size and weight as compared with the system using the power-frequency transformer. A sine-wave AC waveform with substantially less distortion similar to the waveform output by the conventional PWM control can be obtained with a simple construction.