Digital Door Status Detection Circuit for Household Appliances
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Solution Overview
Problem
Existing electric circuit modules for detecting the operational status of household appliance doors, such as washing machines and dryers, are prone to inaccuracies in door closed and locked state detection, leading to compromised appliance operation.
Innovation Solution
A detection circuit module with a diode arranged in series with the actuator and door locking switch, along with a controller circuit module outputting electrical pulse signals, improves detection accuracy and reliability by operating digitally with discrete states, replacing analog resistor/PTC elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If analog resistor/PTC elements are used in the detection circuit, then the circuit can detect door status, but the detection accuracy is compromised due to susceptibility to inaccuracy
Solution Approach 1:
The patent replaces analog resistor/PTC elements with a digital circuit implementation using switches and logic gates. This substitution transitions from an analog detection system prone to drift and inaccuracy to a digital system with discrete, reliable states for detecting door closed and locked conditions
Solution Approach 2:
The invention changes the detection parameter from continuous analog resistance values to discrete digital logic states. By using voltage thresholds and logic level detection instead of resistance measurement, the system achieves more accurate and reliable door status detection
2Reliability
If multiple switches and components are added to improve detection accuracy, then detection reliability improves, but device complexity increases
Solution Approach 1:
The patent combines the door closed detection and door locked detection functions into a single integrated circuit module. By merging these detection functions and using shared components where possible, the design achieves reliable detection without proportionally increasing overall circuit complexity
Solution Approach 2:
The detection circuit module is designed to perform multiple detection functions (door closed status and door locked status) using a unified architecture. The circuit can detect multiple operational states through a single module, reducing the need for separate dedicated circuits for each function
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 enhances the accuracy and energy efficiency of door status detection, reducing manufacturing complexity and cost, while providing redundancy against component failures.
Implementation Method 1
a diode arranged in series with the actuator and the second connecting contact and said diode being arranged electrically in parallel with the door locking switch
Implementation Method 2
the electro-mechanical actuator may include a solenoid actuator
Data Source
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AI summary
A detection circuit module (2) for use with a household appliance door to detect when the door is closed and/or locked, said detection circuit module having a first (10A) and a second (10B) contact configured for electrical connection with the household appliance door so as to be operable with the household appliance door, the detection circuit module including: a door closing switch (30A) arranged electrically in series between the first connecting contact (10A) and an actuator (40A); a door locking switch (50A) arranged electrically in series between the actuator member (40A) and the second connecting contact (20A); and a diode (60A) arranged in series with the actuator (40A) and the second connecting contact (20A) and said diode (60A) being arranged electrically in parallel with the door locking switch (50A).