PURPOSE: To make it possible to rapidly attain a set number of revolution by means of a simple circuit constitution even when supply voltage changes and hence voltage applied to a motor changes during hydro-extracting operation in a washing machine wherein a DC brushless motor is used.
CONSTITUTION: In an agitation type washing machine wherein a DC brushless motor 8 is used to rotate an agitating vane and a washing and hydro-extracting tank, after a DC brushless motor 8 is energized using a predetermined duty factor, which enables the start of hydro-extracting operation, to start a hydro- extracting operation, the duty factor is raised and when a duty factor corresponding to a desired number of revolution which is set by a user has been reached, the duty factor is maintained at a constant value to detect the number of revolution. When the detected number of revolution differs from the set one, the motor is further energized using duty factors having predetermined rising rates and falling rates so that the number of revolution comes close to the set value.
TOKUCHI MASAYUKI
YAMAGAMI KAZUHIKO
YORITA MASAMI
INADA TATSUO
KATO TOYOZO
MITSUBISHI ELECTRIC CORP
JPS62131792A | 1987-06-15 |