Water level sensing apparatus, water supply hose and washing machine having the same
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Solution Overview
Problem
Conventional water level sensing apparatuses in washing machines have low durability and are prone to inaccuracies due to mechanical operation and changes in air pressure and density, leading to unnecessary water and energy consumption.
Innovation Solution
A water level sensing apparatus featuring a plurality of electrodes installed between the inner and outer walls of a circulation hose, connected to a micro-computer that calculates the water level based on capacitance variations, allowing for precise water level measurement without structural modifications to the washing machine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a mechanical water level sensing apparatus is used, then the water level can be sensed through mechanical operation, but the durability is low due to repeated mechanical operation
Solution Approach 1:
The patent replaces the mechanical water level sensing system with a capacitance-based sensing system. Instead of using a mechanical float and core that move physically to sense water level, the invention uses electrodes whose capacitance changes with water level, eliminating mechanical wear and improving durability while maintaining sensing capability.
Solution Approach 2:
The patent eliminates the air pressure-based sensing mechanism and replaces it with a direct capacitance measurement system. The circulation hose is used as the sensing medium itself, with electrodes detecting water level through capacitance changes, removing the need for air pressure transmission and associated mechanical components.
2Measurement precision
If a semiconductor pressure sensor is used, then the water level can be measured through strain gauge deformation, but the measurement precision is affected by changes in air pressure and density
Solution Approach 1:
The patent replaces the pressure sensor-based measurement system with a capacitance-based system. Instead of measuring pressure through diaphragm deformation and strain gauges, the invention directly measures capacitance changes between electrodes as water level changes, eliminating the intermediate pressure transmission step that introduces errors from air pressure and density variations.
Solution Approach 2:
The patent uses the circulation hose and water itself as the sensing medium, eliminating the need for air as an intermediary. The electrodes are inserted into the hose to directly sense water level through capacitance changes, removing air pressure and density as sources of measurement error.
3Ease of operation
If conventional water level sensing apparatuses are operated by received air pressure, then the sensing mechanism can function, but great water level variation occurs due to change of volume within the hose and change of air density, leading to unnecessary water and power consumption
Solution Approach 1:
The patent replaces the air pressure-based operation mechanism with a direct capacitance measurement system. The electrodes detect water level through electrical field changes in the water-hose system, eliminating the need for air pressure transmission and the associated volume and density variations that cause measurement inaccuracies.
Solution Approach 2:
The patent changes the sensing parameter from air pressure to capacitance. By measuring the electrical capacitance between electrodes that changes with water level, the system directly correlates measurement output with water level without the intermediate air pressure parameter that introduces variability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides improved precision in water level measurement, reducing unnecessary water supply and energy consumption while maintaining cost-effectiveness and durability, and can be applied to existing washing machines without altering their structure.
Implementation Method 1
a micro-computer (160) to judge a water level in the main body (169) through variation of a capacitance value of the plural electrodes (167)
Implementation Method 2
Through variation of a capacitance value of the plurality of electrodes, the micro-computer calculates a level of water
Data Source
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AI summary
A water level sensing apparatus (162; 262) which more precisely senses a level of supplied water, a water supply hose (63) and a washing machine having the same is provided. The water level sensing apparatus includes a main body (169) provided with an inner wall (166) and an outer wall (165) and filled with water supplied to the inside of the inner wall, a plurality of electrodes (167) inserted between the inner wall (166) and the outer wall (165) to be opposite to each other, and a micro-computer (160) to judge a water level in the main body (169) through variation of a capacitance value of the plurality of electrodes (167). Therethrough, the water level sensing apparatus (162; 262) more directly measures a water level, as compared to the conventional water level sensing apparatus, thus improving precision in water level measurement. Thereby, the water level sensing apparatus prevents unnecessary water supply and reduces energy consumption.