Magnetized Ferromagnetic Switch Assembly for Contactless Sensing
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Solution Overview
Problem
Conventional switching devices with mechanically controlled contacts face issues such as wear and tear, limited longevity, and degradation in humid environments, while contactless solid-state switches using permanent magnets are costly due to handling and assembly challenges.
Innovation Solution
A contactless switching device utilizing a moveable element with magnetized protrusions and a magnetic field sensor, where the moveable element is made from ferromagnetic material and magnetized using a simple and cost-effective process, allowing for easy manufacturing and operation in various environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If mechanically controlled contacts are used in switching devices, then the device structure is simple and cost-effective, but the contacts wear out after a given number of operations and the device degrades in humid environments
Solution Approach 1:
The patent replaces the mechanical contact system with a magnetic field-based sensing system. A magnetic sensor detects changes in magnetic field caused by a moveable ferromagnetic element, eliminating physical contact between switching components. This substitution resolves the contradiction by maintaining manufacturing simplicity while eliminating contact wear and humidity-related degradation.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the moveable element and the sensing system. Instead of direct mechanical contact, the moveable ferromagnetic element modulates the magnetic field, which is then detected by the magnetic sensor. This intermediary approach allows contactless switching while maintaining simplicity and reliability.
2Reliability
If permanent magnets are used as a source of magnetic field in contactless solid-state switches, then contactless switching is achieved, but manufacturing cost increases due to challenges in handling and assembly
Solution Approach 1:
Instead of using a permanent magnet to generate a magnetic field and detecting its absence/presence, the patent inverts the approach: it uses a magnetic sensor that detects changes in an existing magnetic field caused by a moveable ferromagnetic element. This inversion eliminates the need for permanent magnets, reducing manufacturing complexity and cost while maintaining contactless operation.
Solution Approach 2:
The patent uses a ferromagnetic material that copies or mimics the magnetic properties of permanent magnets without requiring the actual permanent magnet material. The moveable ferromagnetic element becomes magnetized in the presence of a magnetic field, creating a temporary magnetic signature that can be detected, thus achieving the same functional effect as a permanent magnet system but with simpler manufacturing.
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 provides a low-cost, durable, and reliable contactless switching device that is easy to manufacture and suitable for use in humid environments, overcoming the limitations of traditional mechanical and permanent magnet-based solutions.
Implementation Method 1
the moveable element is made from ferromagnetic material and magnetized using a simple and cost-effective process
Implementation Method 2
The moveable element (18) is made from ferromagnetic material
Implementation Method 3
A magnetic field sensor (14) is secured to the housing (24) and positioned to face the plurality of magnetized legs (16, 19, 21)
Data Source
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AI summary
An electrical contactless switch that comprises a housing, a moveable element and a magnetic field sensor. The moveable element is made of a ferromagnetic material and slidably mounted in the housing. The moveable element is adapted to move relative to the housing between a resting position and an engaged position, the moveable element is elastically biased towards the resting position. The moveable element comprises a plurality of magnetized legs spaced from each other and at least part of the magnetized legs is slidably guided in the housing. The magnetic field sensor is secured to the housing and positioned to face the plurality of magnetized legs. The magnetic sensor is configured to detect a magnetic field generated by the magnetized legs as the moveable element is in the engaged position. The moveable element is closer to the magnetic field sensor in the engaged position than in the resting position