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:
Oct. 19, 1999

Filed:

Sep. 15, 1998
Applicant:
Inventors:

Akio Kobayashi, Wako, JP;

Osamu Tsurumiya, Wako, JP;

Takao Kurosawa, Wako, JP;

Nobuo Sugitani, Wako, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
361 23 ; 318254 ; 318281 ; 318293 ; 318446 ;
Abstract

A drive unit for driving an electric motor includes two motor drive circuits disposed in parallel and each consisting of a bridge circuit of switching devices each incorporating a reverse blocking diode, a power switch provided between a power supply and each of the bridge circuits, and a function switch provided between the electric motor and each of the bridge circuits. In case of failure of one bridge circuit, the other bridge circuit is used to replace the failed bridge circuit, thereby continuing controlled operation of the electric motor. While these switches which are associated with one of the bridge circuits are closed, the switches associated with the other bridge circuit are kept open. This arrangement prevents the current from flowing from the power supply into the failed bridge circuit. The failed bridge circuit does not allow the electric motor to act as a generator even when any of the switching devices causes an ON fault.


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