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. 12, 1993
Filed:
Feb. 06, 1991
Munehiko Mimura, Himeji, JP;
Mitsubishi Denki K. K., Tokyo, JP;
Abstract
An excitation current control device for an automotive electromagnetic clutch includes a first and a second transistor 8 and 13 and a current detector resistor 14, coupled in series with the electromagnetic clutch. The first transistor is PWM controlled to control the amount of excitation current through the electromagnetic clutch. The second transistor turns off the excitation current in response to the disconnection signal for the electromagnetic clutch. The current detector amplifier 6 includes, in addition to an operational amplifier 61 and an input and a feedback resistor 63 and 62, an offset resistor 64 for offsetting the base current of the second transistor and the current flowing through a reverse excitation resistor 12 and the detector resistor 14. Alternatively, the offset correction for base current is effected by a software calculation.