Washing machine having a hybrid sensor and a control method thereof

In a washing machine including:

• a main body;
• a water tub provided to inside of the main body;
• a washing tub rotatably mounted to inside of the water tub;
• at least one suspension bar for supporting the water tub;
• and a hybrid sensor which generates an electric signal in response to an ascending or descending displacement of the suspension bar, a method for controlling the washing machine having the hybrid sensor, comprising the steps of:
• a) if a plurality of laundries are initially put into the washing tub after a power-supply is applied to the washing machine, sensing an initial output voltage of the hybrid sensor, and determining a weight of the laundries;
• b) determining an optimum feed water weight corresponding to a sensed laundry weight;
• c) if the output voltage of the hybrid sensor raises due to a water supply step start, determining a voltage difference between a raised output voltage and the initial output voltage as the present feed water weight, and continuously performing a water supply step until the optimum feed water weight is satisfied;
• d) if the output voltage of the hybrid sensor is lowered due to a drain step start, determining a lowered output voltage as a present drain weight, and continuously performing the drain step until the completion of the drain operation is determined;
• and
• e) if a dehydration step starts after the drain step, sensing an output voltage of the hybrid sensor due to a suspension bar's displacement generated in a plurality of intermittent dehydration steps involved in the dehydration step, determining whether there is an unbalance by using the output voltage of the hybrid sensor, and controlling a dehydration operation.