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. 04, 2006
Filed:
Oct. 25, 2004
Shingo Fukamizu, Takatsuki, JP;
Katsuhiro Onishi, Osaka, JP;
Shingo Fukamizu, Takatsuki, JP;
Katsuhiro Onishi, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
The reference signal generation unitintegrates, in the integration circuit, a staircase signal generated by the staircase generation unit, and thereby generates a reference signal VCTA whose signal level changes continuously over time, and which represents a limit value for the supply current. According to the control of the PWM control unit, the bridge rectification circuitmaintains the coil supply current at the limit value, using a current chopper method. Additionally, when the current supply is stopped, the bridge rectification circuitperforms synchronous rectification, where the transistorsandare brought into conduction, and a regenerative current is circulated in a closed circuit formed with the coil. When the reference signal VCTA decreases relatively fast, the synchronous rectification prohibition unitprohibits one of the transistorsandfrom being brought into conduction when the current supply is stopped.