PURPOSE: To accurately detect the speed of rotation of a tank for dewatering and control the speed of rotation of the tank for dewatering on the basis of the detected speed of rotation of the tank for dewatering, in a washing machine having a simple structure.
CONSTITUTION: A tank for washing and dewatering installed rotatably in a water- receiving tank is driven by means of a motor 13 through a clutch. A back electromotive force is generated during inertial running of the motor 13 and detected by a voltage-detecting means 21. On the basis of the output from the voltage-detecting means 21, the running speed of the motor 13 is calculated by an arithmetic means 22. A controlling means 25 for controlling the running of the motor 13 through a power-switching means 26 electrifies and stops electrifying the motor 13 alternately and repeatedly, calculates the running speed of the motor 13 by the arithmetic means 22, based on a wavelength outputted from the voltaged-detecting means 21 during the inertial running of the motor 13 immediately after stopping of electrifying the motor 13, and changes either or both of a period of time when the motor 13 is electrified and a period of time when the motor 13 is not electrified, according to the calculated running speed of the motor 13 so that a predetermined running speed of the motor 13 can be maintained.
| JPS5778894 | DRUM TYPE WASHING MACHINE |
| JP2003284895 | CONTROLLING METHOD OF CLUTCH OF ONE-TUB TYPE WASHING MACHINE |
OTA FUMIO
KENJO YOSHITOYO
