Magnetic Induction Knob Assembly for Wear-Free Signal Encoding
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Solution Overview
Problem
Existing knob switches in household appliances face issues such as wear and tear due to mechanical contact, complex structures, high costs, and limited signal encoding capabilities, particularly in devices like gas stoves and induction cookers.
Innovation Solution
An intelligent knob utilizing a permanent magnet and magnetic induction module to output electrical signals without mechanical contact, featuring a simple structure for easy assembly and low costs, with one magnet and one module enabling unlimited signal encoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an encoder with electric brush is used to convert mechanical rotation signals into electrical signals, then the knob can output encoding signals, but the contact points wear significantly after long-term use, reducing lifespan
Solution Approach 1:
The patent replaces the mechanical contact-based encoder with a magnetic field-based detection system. A permanent magnet is mounted on the rotating shaft, and a magnetic sensor (such as a Hall sensor or magnetic induction sensor) detects the magnetic field changes to generate encoding signals. This substitution eliminates physical contact between moving parts, thereby eliminating wear and abrasion while maintaining the signal encoding function.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the mechanical rotation and the electrical signal output. The permanent magnet converts mechanical rotation into magnetic field variations, and the magnetic sensor converts magnetic field variations into electrical signals. This intermediary approach avoids direct mechanical contact between the rotating shaft and the signal output components, eliminating wear.
2Adaptability or versatility
If an encoder with multiple components is used to output encoding signals, then the knob can achieve signal encoding, but the structure becomes complex and assembly becomes cumbersome
Solution Approach 1:
The patent extracts the core encoding function from the complex encoder assembly and implements it using minimal components: a permanent magnet mounted on the rotating shaft and a magnetic sensor mounted on the housing. This extraction eliminates unnecessary components while preserving the essential signal encoding capability, thereby simplifying the structure and reducing assembly complexity.
Solution Approach 2:
The magnetic field-based encoding system serves multiple functions with a single simple structure: it provides rotational position detection, rotational direction detection, and rotational speed detection. The permanent magnet and magnetic sensor combination can generate various encoding patterns (such as quadrature encoding) to support different control requirements, achieving high adaptability with low structural complexity.
3Adaptability or versatility
If an encoder with electric brush and contact chip is used to achieve binary code output, then the knob can output encoded signals, but the number of conductive and insulating areas is limited, restricting the number of encoded signals
Solution Approach 1:
The patent changes the encoding parameter from physical contact patterns (conductive and insulating areas) to magnetic field patterns. By varying the magnetic pole arrangement of the permanent magnet (such as using multiple poles or different pole configurations), the system can generate a large number of different encoding patterns without adding physical contact elements. This allows for virtually unlimited encoded signals while maintaining a simple structure.
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 intelligent knob achieves long service life with no abrasion, easy assembly, and unlimited signal encoding, enhancing control flexibility and functionality through magnetic induction.
Implementation Method 1
The PCBA includes: a magnetic induction module, and the magnetic induction module is matched with the permanent magnet through magnetic induction
Data Source
AI summary
An intelligent knob includes: a bottom housing, a rotating assembly, an inner support assembly, a small gear, a PCBA, a display module, a knob outer ring, and a permanent magnet. An upper side of the bottom housing defines an annular cavity and a small gear installation position. The rotating assembly includes: a large gear rotatably disposed in the annular cavity and a knob support ring. The inner support assembly is disposed on an upper side of the rotating assembly and connected to the bottom housing. The rotating assembly is capable of rotating at a lower side of the inner support assembly. The small gear is installed on the small gear installation position and meshes with the large gear. The permanent magnet is installed in the small gear. The PCBA is installed on the inner support assembly and includes a magnetic induction module matched with the permanent magnet.