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:
Nov. 02, 1982

Filed:

Dec. 03, 1981
Applicant:
Inventors:

Shigeki Saito, Katsuta, JP;

Osamu Koizumi, Ibarakimachi, JP;

Syoichi Kawamata, Hitachi, JP;

Assignee:

Hitachi, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G05B / ;
U.S. Cl.
CPC ...
318473 ; 318471 ; 318472 ; 318334 ;
Abstract

Disclosed is an apparatus for controlling a motor unit including a variable-speed reversible main motor for driving a load and a subsidiary motor for driving a fan. The control apparatus comprises a temperature sensor circuit sensing the temperature of the main motor and generating a first output signal when the temperature of the main motor exceeds a first predetermined level, a second output signal when the main motor temperature exceeds a second predetermined level higher than the first predetermined level and a third output signal when the main motor temperature drops to a level lower than the first predetermined level, and a control circuit connected to the temperature sensor circuit for energizing the subsidiary motor in response to the first output signal, deenergizing the main motor in response to the second output signal and deenergizing the subsidiary motor in response to the third output signal.


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