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. 25, 2000

Filed:

Oct. 06, 1999
Applicant:
Inventors:

Yoshiki Noro, Wako, JP;

Yoshinobu Mukai, Wako, JP;

Shinzi Hironaka, Wako, JP;

Mitsunori Kawashima, Wako, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02K / ;
U.S. Cl.
CPC ...
318138 ; 318254 ; 318432 ; 318434 ; 318439 ; 361 23 ; 361 24 ; 361 31 ; 361 33 ; 361 87 ; 361 91 ;
Abstract

In a motor drive apparatus, a motor drive circuit includes an H bridge circuit composed of four field effect transistors or FETs, and resistors each having electrical resistance sufficiently higher than that of each of the FETs which would be presented when the FET has an ON-state trouble. These resistors are connected in parallel to the respective FETs. To perform a ON-state trouble detecting test on the individual FETs, an OFF signal is fed to all the FETs. If all the EFTS are free of the ON-state trouble, electric potential, representing a result of higher potential of a battery being divided by the resistors, appears at two input terminals of an electric motor connected to the motor drive circuit. If two of the FETs, having their drains connected to a higher-potential electrode of the battery, have the ON-state trouble, the higher potential of the battery appears at the two terminals of the electric motor. If the other two FETs, having their sources connected to a lower-potential or ground electrode of the battery, have the ON-state trouble, the lower or ground potential of the battery appears at the two terminals of the electric motor. These potential appearing at the motor terminals is detected via respective potential detectors.

Published as:
JP3034508B1; JP2000152691A; DE19953606A1; US6094021A;

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