Dishwasher Drain Pump Current Sensing for Filter Clog Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for detecting dishwasher filter clogging, such as monitoring the current drawn by the circulation pump, often result in erroneous decisions due to confusion with insufficient water levels, leading to inadequate washing performance.
Innovation Solution
A device and method that measure the operating current of a drain pump motor downstream of the sump, comparing it to predetermined threshold values to accurately determine filter clogging, distinguishing between clogged filters and insufficient water levels by assessing the drain pump's torque and water flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the circulation pump current is monitored to detect filter clogging, then filter clogging detection capability is provided, but false positives occur when water level is insufficient
Solution Approach 1:
The patent segments the detection function by using separate pumps for different purposes: the circulation pump for washing and the drain pump for draining. This segmentation allows independent monitoring of each pump's current, enabling accurate filter clogging detection through the drain pump without interference from water level variations that affect the circulation pump.
Solution Approach 2:
The patent introduces the drain pump as an intermediary device for detection purposes. By measuring the current of the drain pump during the draining phase, the system obtains an accurate indicator of filter clogging status without the confounding factor of varying water levels that plagues circulation pump-based detection methods.
2Use of energy by moving object
If the circulation pump load is reduced due to insufficient water, then energy consumption decreases, but filter clogging detection becomes erroneous
Solution Approach 1:
The patent employs dynamic operational phases: a washing phase with the circulation pump and a draining phase with the drain pump. By switching between these dynamic phases, the system creates optimal conditions for accurate filter clogging detection during the draining phase when water level effects are eliminated.
3Device complexity
If a simple current threshold comparison is used, then detection simplicity is maintained, but detection accuracy may be insufficient without proper timing
Solution Approach 1:
The patent performs preliminary action by initiating the draining phase specifically for detection purposes before making the filter clogging determination. This preliminary draining action ensures that water level effects are eliminated and the drain pump current accurately reflects filter clogging status, enabling precise detection through simple threshold comparison.
Solution Approach 2:
The drain pump serves a dual function: it performs the necessary draining operation and simultaneously provides the detection signal through its current measurement. This self-service approach eliminates the need for separate detection hardware, maintaining simplicity while achieving high detection precision.
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
This approach provides reliable detection of filter clogging, avoiding false positives from low water levels and ensuring accurate assessment of filter status, thus maintaining optimal dishwasher performance.
Implementation Method 1
measuring operating current of a motor driving a dishwasher drain pump
Data Source
Figure 1
Figure 2
AI summary
The present invention relates to a method of, and a device for, detecting clogging of a dishwasher filter. The device is arranged to drain the dishwasher on process water, measure operating current of a motor driving a dishwasher drain pump and determine whether the dishwasher filter is clogged based on the measured drain pump motor operating current.