Magnetic Field Sensor Module for Low Voltage Switch Position Reporting

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Solution Overview

Problem

Existing devices for reporting the switch position of low-voltage switches lack operational reliability and are not easily retrofittable or space-efficient, often being susceptible to interference and requiring additional width in low-voltage distribution boards.

Innovation Solution

A signaling device with a magnetic field generator and sensor module that is mechanically coupled to the switch, using a plate-shaped sliding body and Hall element or reed contact to form an electrical signal, is designed to be compact, interference-resistant, and can be easily retrofitted, with optional optical indication and digital signal processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical auxiliary switch with contact points is used, then the device can report switch position, but the device is susceptible to electrical and magnetic interference reducing operational reliability

Engineering Contradiction:
Improveoperational reliabilityVSAvoidsusceptibility to electrical and magnetic interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical/electrical contact-based auxiliary switch with a magnetic field-based sensing system. A magnetic field generator (permanent magnet or electromagnet) is coupled to the movable contact piece, and a magnetic field sensor (Hall element or reed contact) detects the magnetic field changes to determine switch position. This substitution eliminates direct electrical contacts that are susceptible to interference and arcing, thereby improving reliability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a magnetic field as an intermediary between the movable contact piece and the sensor. Instead of direct electrical contact, the magnetic field serves as the coupling medium that transmits position information from the switch to the sensor without being affected by electrical interference or arcing, thus resolving the susceptibility to harmful factors.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a traditional auxiliary switch device is installed, then switch position can be reported, but additional width is required in the low-voltage distribution board

Engineering Contradiction:
Improveretrofit capabilityVSAvoidwidth in distribution board
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

The patent merges the signaling device with the existing switch housing structure. The magnetic field generator is integrated into the switch's movable contact piece, and the sensor is mounted on the switch housing or adjacent structure. This combination eliminates the need for separate auxiliary switch devices that would require additional width in the distribution board, enabling easy retrofitting of existing installations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The signaling components (magnetic field generator and sensor) are nested within or on the existing switch housing structure. The magnetic field generator is incorporated into the movable contact piece assembly, and the sensor is positioned on the housing or adjacent structure, effectively nesting the reporting function within the existing spatial envelope of the switch without requiring additional width.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Productivity

If mechanical contact pieces are used for switching, then the switch can open and close circuits, but switching arcs are generated causing interference

Engineering Contradiction:
Improveswitching operation capabilityVSAvoidswitching arcs
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical contact-based switching with a magnetic field-based detection system. The magnetic field generator follows the movement of the movable contact piece during switching operations, and the magnetic field sensor detects the position changes without being exposed to switching arcs. This substitution maintains the switching capability while eliminating the harmful effects of arcs on the sensing components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 high operational reliability, allows for easy retrofitting without increasing the device's width, and offers both electrical and optical reporting of switch positions, even in the event of signal circuit failure, while minimizing space usage and interference susceptibility.

Implementation Method 1

The release contains at least one magnetic field generator, which is guided in a variable position by a movable contact piece of the low-voltage switch, for generating or amplifying a magnetic field

Methodology Applied
Scientific EffectMagnetic field generation: Electromagnet

Implementation Method 2

The auxiliary switch is designed as a sensor module and has at least one magnetic field sensor interacting with the magnetic field sensor for opening and closing the signal circuit after a change in position of the magnetic field sensor caused by a switching operation of the low-voltage switch

Methodology Applied
Scientific EffectHall effect: Hall Effect

Implementation Method 3

at least one magnetic field sensor interacting with the magnetic field sensor

Methodology Applied
Scientific EffectMagnetic field interaction: Magnetic Field

Data Source

PatentEP2642499B1Device for reporting the setting of a low voltage circuit switch with such a switch
Publication Date: 2014.06.04 ABB (SCHWEIZ) AG
  • EP2642499B1 patent drawingFigure 1
  • EP2642499B1 patent drawingFigure 2

AI summary

The device (V) has an auxiliary switch designed as sensor module (40), and a magnetic field sensor (42) i.e. Hall element, connected with a magnetic field transmitter (36). The sensor module is fastened to an operation side (11) of a low tension switch (S), where the operation side is turned away from a fitting side such that a trigger (30) comprises a plate-like sliding body (32) i.e. permanent magnet. The transmitter is arranged on the sliding body that is movably supported along a guiding path (33) formed in a region at the operation side of inner surfaces of housing halves. The plate-like sliding body is made of ferro-magnetic plastic material.