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. 04, 2005
Filed:
Aug. 29, 2003
Hiroki Matsunaga, Takatsuki, JP;
Shingo Fukamizu, Takatsuki, JP;
Hiroki Matsunaga, Takatsuki, JP;
Shingo Fukamizu, Takatsuki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A reference signal generation unit integrates a staircase signal, to produce reference signal VCTA whose waveform has no abrupt changes in level and which shows a current limit value. A PWM reference signal generation unit generates a PWM reference signal. A supply current measurement unit measures a supply current to a coil. A PWM control unit compares reference signal VCTA with the measurement value of the supply current measurement unit in each period of the PWM reference signal, and sets each transistor in a bridge rectification circuit in a conducting state or a nonconducting state according to the comparison result. In this way, the supply current to the coil is controlled to approach the current limit value shown by reference signal VCTA.