Washer and method of performing spinning operation

Abstract

A washer and a method of performing a spinning operation are disclosed. The washer includes a tub which stores clothes to be washed, and a motor which rotates the tub. It also includes a microprocessor which generates a pump driving signal having duty ratios to power on and off a drain pump during at least one preliminary and a main sub-cycles of a selected spinning operation. The method of performing the spinning operation includes accelerating, decelerating, and maintaining a certain speed during the at least one preliminary sub-cycle of the spinning operation. However, the main sub-cycle includes accelerating and maintaining another certain speed. According to the principles of the present invention, the washer and the method of performing the spinning operation prevent the drain pump from not only overheating but also creating power loss.

1 . A method of performing a spinning operation for a washer having a drain pump and a motor, the method comprising: 
 initiating a selected spinning operation including at least one preliminary sub-cycle and a main sub-cycle after performing a washing operation;    generating a pump driving signal having at least two different duty ratios during the selected spinning operation, wherein the drain pump is driven by the pump driving signal; and    assigning one of the at least two different duty ratios to each of the at least one preliminary and the main sub-cycles during the spinning operation to drive the drain pump.    
   
   
       2 . The method of  claim 1 , wherein the at least two different duty ratios are selected in an ascending order to be applied to each of the at least one preliminary and the main sub-cycles during the spinning operation  
   
   
       3 . The method of  claim 1 , wherein the at least one preliminary sub-cycle includes 
 accelerating the motor to a first speed,    decelerating the motor to a second speed, and    maintaining the second speed for a first pre-determined time.    
   
   
       4 . The method of  claim 1 , wherein the main sub-cycle includes 
 accelerating the motor to a first speed, and    maintaining the first speed for a first pre-determined time.    
   
   
       5 . The method of  claim 1 , wherein the at least one preliminary sub-cycle includes a first sub-cycle and a second sub-cycle, the first sub-cycle comprising: 
 accelerating the motor to a first speed;    decelerating the motor to a second speed, wherein the second speed is lower than the first speed; and    maintaining the second speed for a first pre-determined time, the second sub-cycle comprising:    accelerating the motor from the second speed to a third speed, wherein the third speed is faster than the second speed;    decelerating the motor back to the second speed; and    maintaining the second speed for the first pre-determined time, the main sub-cycle comprising:    rotating the motor from the second speed to the third speed; and    maintaining the third speed for a second pre-determined time.    
   
   
       6 . The method of  claim 5 , wherein the drain pump is driven by 
 applying a pump driving signal having a first duty ratio during the first pre-determined time; and    applying a pump driving signal having a second duty ratio during the second pre-determined time, wherein the second duty ratio is greater than the first one.    
   
   
       7 . The method of  claim 5 , wherein the first, second, and third speeds are 180, 100, and 350 revolutions per minute (RPM), respectively.  
   
   
       8 . A washer comprising: 
 a tub containing clothes to be washed;    a motor rotating the tub to perform a spinning operation;    a drain pump draining water from the tub during the spinning operation; and    a microprocessor generating a pump driving signal having at least one duty ratio to power on and off the drain pump.    
   
   
       9 . The method of  claim 8 , wherein the microprocessor selectively applies the at least one duty ratio to at least one preliminary sub-cycle and a main sub-cycle of the spinning operation.  
   
   
       10 . The method of  claim 9 , wherein the at least one duty ratio is selected in an ascending order to be applied to each of the at least one preliminary and the main sub-cycles during the spinning operation.  
   
   
       11 . A computer software product, comprising: 
 a computer-readable medium storing program code for controlling operations of a washer, the program code, when executed by the microprocessor, causing the microprocessor perform    a first sub-cycle, a second preliminary sub-cycle, and a main sub-cycle of a spinning operation, wherein the first sub-cycle includes 
 rotating the motor up to a first speed,  
 decelerating the motor to a second speed, wherein the second speed is lower than the first speed,  
 maintaining the second speed for a first pre-determined time, and  
 applying a pump driving signal having a first duty ratio to drive the drain pump during the first pre-determined time, the second sub-cycle includes  
 rotating the motor up to a third speed from the second speed, wherein the third speed is higher than the second speed,  
 decelerating the motor back to the second speed,  
 maintaining the second speed for the first pre-determined time, and  
 applying a pump driving signal having the first duty ratio to drive the drain pump during the first pre-determined time, and the main sub-cycle includes  
 rotating the motor from the second speed to the third speed,  
 maintaining the third speed for a second pre-determined time, and  
 applying a pump driving signal having a second duty ratio during the second pre-determined time to drive the drain pump, wherein the second duty ratio is greater than the first ratio.