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:
Oct. 31, 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
A reference signal generation unitgenerates a reference signal VCA representing a limit indicator. Under the control of a PWM control unit, a bridge rectification circuitcontrols the current supplied to a coilto the limit indicator, using a current chopper method. Therewith, the circuitimplements synchronous rectification where transistorsandare brought into conduction when the current supply is stopped, forming a closed circuit with the coil, and a regenerative current circulates in the closed circuit. During a time period when the reference signal is decreasing relatively rapidly, a SR prohibition unitprohibits the transistororfrom being brought into conduction when the current supply is stopped, and thereby the decay of regenerative current is accelerated.