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, 1995

Filed:

Dec. 17, 1993
Applicant:
Inventors:

Kazunobu Nagai, Aichi, JP;

Ichiro Hongo, Yokohama, JP;

Nobuo Matsui, Yokohama, JP;

Assignee:

Kabushiki Kaisha Toshiba, Kanagawa, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318801 ; 318811 ; 62151 ; 622284 ;
Abstract

An inverter controlling an air conditioner including a brushless motor serving as a compressor motor. A microcomputer detects the rotational position of a rotor of the brushless motor from signals obtained by comparison of each of terminal voltages of the motor windings with a reference voltage in order to determine a commutation time. In a normal operation, the microcomputer forms, according to a normal energization signal forming pattern, energization signals corresponding to every commutation time at every occurrence of the commutation time, so that the motor windings are sequentially energized. When frost forms on an outdoor heat exchanger of a heat pump during a warming operation and a defrosting operation is necessary, the energization signals are formed according to a loss increasing energization signal forming pattern so that loss increasing energization signals for causing the rotor to produce counter torque are added to the respective energization signals formed according to the normal pattern. As a result, the brushless motor loss is increased and the brushless motor generates heat. The generated heat is used for defrosting the outdoor heat exchanger.


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