Appliance Lock Voltage Encoding for Single-Wire State Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing locking mechanisms in washing machines require multiple independent electrical conductors to connect multiple switches to the appliance controller, increasing wiring costs and complexity.
Innovation Solution
Encoding the multiple states of physically separate switches into distinct electrical levels that can be conveyed over a single wire, using resistors to control current through a signal wire and decoding these signals at the appliance controller with an analog-to-digital converter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple independent electrical conductors are used to connect multiple switches to the appliance controller, then reliable detection of door position and lock state is improved, but wiring cost and complexity increase
Solution Approach 1:
The patent combines multiple independent electrical conductors into a single shared signal wire. Multiple switches (door position switch, lock sensing switch, unlock sensing switch) are connected to the appliance controller through this single wire, eliminating the need for separate conductors for each switch while maintaining reliable state detection.
Solution Approach 2:
The single signal wire serves multiple functions by carrying encoded information from multiple different switches. The wire is used to detect door position, lock engagement state, and unlock state simultaneously through voltage level encoding, making the wiring system multi-functional rather than requiring dedicated wires for each detection function.
2Measurement precision
If multiple independent electrical conductors are used to connect multiple switches, then accurate state detection is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges multiple conductor requirements into a single wire implementation, reducing the quantity of wiring materials needed and simplifying the manufacturing process. The encoder circuit combines signals from multiple switches into a single encoded stream that travels over one wire, lowering both material costs and assembly complexity.
Solution Approach 2:
The patent changes the electrical parameters (voltage levels) of the single signal wire to encode multiple switch states. By using different voltage levels (e.g., 5V for locked, 2.5V for unlocked, 0V for open) on the same wire, the system achieves precise state detection without requiring multiple physical conductors, thereby reducing manufacturing costs.
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 reduces the need for multiple wires, allowing for redundant switch signals without increasing wiring harness costs and enabling energy-efficient actuators while maintaining lock and unlock confirmation signals.
Implementation Method 1
A first and second resistor each having different unique values are each attached to a corresponding one of the door position switch and the lock sensing switch so that corresponding switches control current through the corresponding attached resistors
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A lock system for an appliance providing multiple detection switches (24, 30, 31) for lid closure and lid locking encodes the switch states as different voltages on a single signal line (42) to reduce wiring harness costs.