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:
May. 23, 1989

Filed:

Nov. 04, 1987
Applicant:
Inventor:

Kiichiro Shimura, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318286 ; 388815 ;
Abstract

A motor drive circuit fo driving a reversible motor selectively in a forward or reverse direction comprises a main switch for connecting electrically the motor drive circuit to a power supply source, auxiliary switch circuitry for determining a current path along which a current is to be supplied from the power supply source to the reversible motor and duration in which the current is supplied to the motor, current supply control circuitry for detecting the current path determined by the auxiliary switch circuitry and causing the current to flow along the determined electric path, hold circuitry for holding the operating state of the current supply control circuitry, oscillation circuitry operable in response to the operation of the main switch establishing the connection to the power supply source to supply a reset signal to the hold circuitry and cause the current supply control circuitry to perform current detecting operation through the hold circuit, and current interrupting circuitry for breaking the connection to the power supply source in response to detection of interruption of the current flow to the motor, wherein the direction in which the motor is rotated is alternately changed over upon every closing operation of the main switch.


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