Method for sensing water level and vibration of washing machine and apparatus therefor

A water level and vibration detection method for a washing machine, comprising the steps of:

• measuring a resonant frequency when a water level of a washtub is zero, and there is not a laundry in the washtub in a water level sensor which is directed to changing a water pressure variation based on a water level of a washtub into a resonant frequency for thereby detecting a water level of the washtub;
• setting the resonant frequency as a reference resonant frequency;
• checking whether an induction motor is operated for rotating the washtub;
• measuring a resonant frequency based on the water level sensor when the induction motor is in the operation mode and obtaining a deviation with respect to the reference resonant frequency;
• and
• determining whether the induction motor is continuously operated based on a comparison between the thusly obtained deviation and a set reference deviation.

A water level and vibration detection method for a washing machine, comprising the steps of:

• changing an induction of a coil based on a movement in an inner space of a coil by a variation of a water pressure in accordance with a water level of a washtub in the washing mode;
• changing the induction of the coil based on a movement in an inner space of the coil by a variation in the horizontal and vertical directions in accordance with an eccentric rotation of the washtub in the dehydration mode;
• changing a resonant frequency by adding a set capacitance value to a varied value of the inductance which is obtained based on the operational modes;
• and
• controlling a washing operation by judging the water level and vibration based on the variation of the resonant frequency obtained in the operation modes.

A water level and vibration detection method for a washing machine, comprising the steps of:

• changing an inductance value based on a movement in an inner space of a coil unit having more than at least two inductances based on a variation of a water pressure in accordance with a water level of a washtub;
• changing more than at least one inductance including an inductance with respect to the vertical direction at the coil unit as a sliding member is freely moved with respect to a support member in which there are a vibration area and a non-vibration area in accordance with an eccentric rotation of the washtub;
• adding a certain capacitance to the varied inductance and changing to a resonant frequency;
• and
• controlling the operation modes of the washing operation by judging the water level or vibration using a varied value of the resonant frequency in accordance with the washing operation.

A water level and vibration detection apparatus for a washing machine, comprising:

• a sealing state maintaining means which is installed in a housing connected with a tank and a water pressure transfer path and is vertically moved based on a water pressure in accordance with a water level of a washtub;
• a coil having an inductance and installed at an inner center wall portion of the housing;
• a magnetic medium engaged to an upper surface of the sealing state maintaining means and vertically moving in an inner space of the coil in accordance with the water pressure and varying the inductance;
• a support member positioned in an inner space of the coil at a certain distance from the upper portion of the magnetic medium and vertically moving together with the magnetic medium by the water pressure and having its upper surface which is slanted at a certain angle;
• a sliding member having a certain diameter, vertically moving along an inclination surface based on an eccentric rotation of the washtub and varying the inductance of the coil;
• and
• a waveform shaping means for adding a certain capacitance to a variation value of the inductance of the coil, generating a resonant frequency, stabilizing the resonant frequency to a voltage waveform and selectively measuring the water level and eccentricity.

A water level and vibration detection apparatus for a washing machine, comprising:

• a sealing state maintaining means installed in a housing connected with a tank and a water pressure transfer path and expanding by a water pressure based on the water level in a washtub and vertically moving;
• a coil unit having more than at least two inductances and installed at an inner center wall portion of the housing;
• a magnetic medium engaged to an upper surface of the sealing state maintaining means and vertically moving in an inner space of the coil unit based on the water pressure and changing a certain inductance;
• a support member installed in an inner space of the coil unit at a certain distance from the upper portion of the magnetic medium and vertically moving in the inner space of the coil unit together with the magnetic medium by the water pressure and having its upper surface formed at an inclination angle with respect to the center portion;
• a sliding member having a certain diameter, freely moving along an inclination surface of the support member based on an eccentric rotation of the washtub and varying one inductance at the coil unit;
• and
• a waveform shaping means for adding a fixed capacitance to an inductance variation of the coil unit, generating a resonant frequency, stabilizing the resonant frequency to a voltage waveform, and selectively measuring the water level and the vibration in each direction.