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:
Aug. 29, 2000
Filed:
Mar. 01, 1999
Masanori Sugiyama, Aichi-ken, JP;
Chiaki Honma, Aichi-ken, JP;
Aisin Seiki Kabushiki Kaisha, Kariya, JP;
Abstract
A rising saw tooth signal generating circuit generates a rising saw tooth signal having a constant amplitude and a constant period which corresponds to a frequency being slightly higher than the human audible frequency range. The rising saw tooth signal generating circuit also generates a binary signal which generates a reference chopping timing synchronizing with the rising saw tooth signal. The rising saw tooth signal is inverted and a descending saw tooth signal is generated. The descending saw tooth signal is added to the reference current signal and a binary signal is generated by the result of the comparison between the addition signal and the actual current signal. A flip-flop generates a signal which reaches a low level whenever the binary signal is descended and which reaches a high level whenever the reference chopping timing comes. A further binary signal which moves to the high level at the feeding of the current and the signal are supplied to the AND gate. The output signal of the AND gate and the signal is supplied to an AND gate and a binary signal for driving a switching element is obtained.