Dishwasher Bubble Detection Using Wash Motor Current Monitoring
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Solution Overview
Problem
Dishwashers using non-specialized detergents often generate excessive bubbles, leading to increased tub pressure, reduced capacity, and potential leakage due to blocked air guide holes, which existing technologies fail to effectively prevent or sense in advance.
Innovation Solution
A method to control a dishwasher by determining excessive bubble generation based on the current applied to the wash motor, involving a predetermined period of detergent mixing, nozzle adjustment, and bubble-sensing steps to accurately assess bubble levels and perform a bubble-removing process before leakage occurs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a general dishwashing detergent is used instead of a detergent for exclusive use in a dishwasher, then cleaning effectiveness is improved, but excessive bubbles are generated leading to increased pressure and potential leakage
Solution Approach 1:
The control unit detects excessive bubbles before they cause harmful effects by monitoring motor current during the washing cycle. When excessive bubbles are detected, the system performs a preliminary draining operation to remove the bubbles, preventing pressure buildup and leakage before they occur.
Solution Approach 2:
The system continuously monitors the current consumed by the wash motor during operation. When the current deviates from the normal range indicating excessive bubble generation, the control unit receives feedback and automatically initiates a bubble removal process by draining water through the drain pump, creating a closed-loop control system that prevents harmful effects.
2Reliability
If the temperature in the tub is increased during the main washing process, then washing performance is improved, but the amount of bubbles increases sharply
Solution Approach 1:
The control unit performs preliminary detection of excessive bubbles by monitoring motor current before the temperature increase causes severe bubble generation. When excessive bubbles are detected early, the system drains water to remove bubbles proactively, preventing the sharp increase in bubble amount that would occur with continued heating.
Solution Approach 2:
The system uses real-time monitoring of motor current as feedback during the heating process. When the current indicates excessive bubble generation due to temperature increase, the control unit automatically interrupts or adjusts the heating process and initiates draining, creating a feedback mechanism that balances washing performance with bubble control.
3Stress or pressure
If air guide holes in the tub are blocked by excessive bubbles, then pressure adjustment is compromised, but this leads to further increase in bubbles and pressure
Solution Approach 1:
The control unit performs preliminary detection of excessive bubbles by monitoring motor current before the bubbles can block the air guide holes and compromise pressure adjustment. By detecting bubbles early and draining water proactively, the system prevents the blockage of air guide holes and the subsequent harmful pressure buildup.
Solution Approach 2:
The system uses motor current monitoring as feedback to detect conditions that would lead to air guide hole blockage. When excessive bubbles are detected, the control unit initiates draining operations to remove bubbles before they can block the air guide holes, maintaining proper pressure adjustment functionality and preventing the vicious cycle of increasing bubbles and pressure.
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
Prevents bubble leakage by accurately sensing and removing excessive bubbles, ensuring the dishwasher operates safely and efficiently, even with non-specialized detergents, by stabilizing current values and adjusting water supply through the top nozzle.
Implementation Method 1
In the case in which heat is applied to wash water, which is mixed with a detergent and is circulated in the sealed space by the wash pump, there may occur a problem in that a large amount of bubbles is generated.
Implementation Method 2
The amount of bubbles, which is generated by a detergent other than a detergent for exclusive use in a dishwasher, may further increase as the pressure or temperature in the tub increases.
Implementation Method 3
determining whether an amount of bubbles is excessive based on a value of current applied to the wash motor
Data Source
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AI summary
A method of controlling a dishwasher is disclosed. The method includes supplying water (S2100) to a sump, driving a wash pump (S2200) using a wash motor, introducing (S2250) a detergent into a tub, and determining (S2300) whether the amount of bubbles is excessive based on the value of current applied to the wash motor. The determining whether the amount of bubbles is excessive is performed after a lapse of a predetermined period of time since the start of the introducing the detergent into the tub.