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.

Date of Patent:
Jul. 04, 1989

Filed:

Sep. 27, 1988
Applicant:
Inventors:

Hidekazu Oshizawa, Higashimatsuyama, JP;

Ryoichi Harada, Higashimatsuyama, JP;

Masami Okano, Higashimatsuyama, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G05F / ; H01H / ;
U.S. Cl.
CPC ...
323222 ; 323284 ; 361152 ; 361153 ;
Abstract

In a drive circuit device for an inductive load, the inductive load and a detecting resistor are incorporated in a current supply circuit in series relation to a drive transistor. An operational amplifier is operative in response to detecting voltage fed-back from the detecting resistor, for controlling the drive transistor, in turn, for controlling supply current flowing through the inductive load to a predetermined value. Turning-on and -off of the drive transistor are controlled by a switching element operative in response to a control signal, thereby carrying out current supply to an inductive load and stoppage of the current supply. A feed-back circuit is provided, in which a response element supplies feed-back current to be controlled by the operational amplifier, to the feed-back resistor, in response to the turning-off of the drive transistor. The operational amplifier carries out feed-back control without being saturated, even at the stoppage of the current supply to the inductive load.


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