Unbalance detecting device and method of washing machine

Abstract

An unbalance detecting method of a washing machine, wherein an unbalanced mass of a washing machine is accurately detected and classified according to input voltage variation when the unbalance is detected utilizing a ripple width of a current by a current sensor, thereby preventing errors from occurring in spin-dry process, the method comprising the steps of increasing the speed of the motor to a predetermined revolution per minute (rpm); detecting a variation of an AC input voltage according to input voltage detecting means; detecting a ripple current of an AC input current according to input current detecting means; obtaining a difference between a maximum value and a minimum value of a ripple current detected by the input current detecting step to thereby determine whether a ripple width of the current is larger than a predetermined value; calculating an unbalanced mass according to the input voltage value detected at the input voltage detecting step when it is determined that the ripple width of the current is not larger than the predetermined value; and controlling the speed of the motor according to the unbalanced mass calculated at the unbalanced mass calculating step to perform a spin-dry operation.

Dependencies are inferred from the claim text.