SMPS Module Self-Diagnosis for Fault Detection in Washing Appliances
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Solution Overview
Problem
The assembly of Switched-Mode Power Supply (SMPS) modules in electric appliances is challenging, leading to potential damages and faults, which are difficult to detect reliably and efficiently during manufacturing, requiring costly and time-consuming electrical tests.
Innovation Solution
A method and circuit for quickly detecting damages in SMPS module components, particularly capacitive components, by using a control unit that receives a test DC supply voltage and provides fault indications if it falls outside predetermined value ranges, allowing for early detection of faults without expensive test apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical tests are performed to detect SMPS module faults during manufacturing, then reliability of fault detection is improved, but device complexity and production costs increase due to requiring costly test apparatus
Solution Approach 1:
The SMPS module performs self-diagnosis by using its own internal control unit to monitor its output voltages. The control unit reads the actual DC supply voltages from its own output terminals and compares them against expected reference values, eliminating the need for external test equipment. This self-service approach maintains high detection reliability while avoiding additional complex test apparatus.
Solution Approach 2:
The control unit implements a feedback mechanism where it continuously monitors its own output DC supply voltages and compares them against predetermined reference values. When a deviation is detected, the control unit generates a fault indication. This internal feedback loop provides reliable fault detection without requiring external test equipment, thus resolving the contradiction between detection reliability and device complexity.
2Measurement precision
If electrical tests are performed to detect SMPS module faults during manufacturing, then measurement precision is improved, but productivity decreases due to excessive test times
Solution Approach 1:
The control unit is pre-configured with reference values for the DC supply voltages during the design phase. During manufacturing, the unit immediately compares actual voltages against these pre-stored references without requiring external test equipment setup or calibration procedures. This preliminary preparation enables instant fault detection with high precision, maintaining measurement accuracy while eliminating time-consuming test procedures.
Solution Approach 2:
The SMPS module performs its own voltage measurements and comparisons using internal circuitry and the control unit. This self-service capability eliminates the need for external test apparatus setup, calibration, and operation, thereby maintaining high measurement precision while significantly reducing the time required for fault detection during manufacturing.
3Ease of manufacture
If manual assembly operations are performed on SMPS modules, then ease of manufacture is improved, but reliability worsens due to increased risks of unintentional damages
Solution Approach 1:
The control unit is pre-programmed with reference voltage values and fault detection thresholds before the SMPS module leaves the assembly line. This preliminary configuration ensures that even if manual assembly introduces variations or potential damages, the module will automatically detect and report faults based on pre-established criteria, maintaining reliability despite manual handling.
Solution Approach 2:
The internal feedback mechanism continuously monitors output voltages and compares them against reference values. If manual assembly operations cause any component shifts, soldering issues, or damage affecting voltage output, the feedback system immediately detects the deviation and generates a fault indication. This real-time monitoring maintains reliability even when ease of manufacture requires manual assembly operations.
Data Source
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AI summary
A washing and/or drying appliance (100) is proposed. The appliance comprises an electric power supply assembly (130,330,430) configured to receive an AC supply voltage and to provide a DC supply voltage (VDC) therefrom, the DC supply voltage (VDC) being adapted to power electrically-operated devices of the appliance (100). The electric power supply assembly (130,330,430) comprises an output module for providing the DC supply voltage (VDC), and a control unit (215) electrically coupled to at least one component (C) of the output module for receiving a test DC supply voltage (VDC,TEST) corresponding to the DC supply voltage (VDC). The control unit (215) is further configured to provide fault indications indicative that the least one component (C) of the output module is affected by damages upon detecting that said test DC supply voltage (VDC,TEST) has a value outside a values range comprising a predetermined value of the test DC supply voltage (VDC,TEST).