Ring-Shaped Hall Sensor Phase Shift Direction Measurement

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Solution Overview

Problem

Existing magnetic field sensors require complex mathematical calculations to determine the direction of a magnetic field in a plane, which is inefficient and cumbersome.

Innovation Solution

A magnetic field sensor with a ring-shaped, electrically conductive well and multiple contacts that transforms spatial information into a time signal using a moving vertical Hall element, where the phase shift between the output signal and a reference signal indicates the magnetic field direction, eliminating the need for complex calculations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a Hall-effect sensor is used to measure magnetic field direction, then the measurement capability is achieved, but complex mathematical calculations are required to process the output signals

Engineering Contradiction:
Improvemagnetic field direction measurementVSAvoidmathematical calculation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transforms the spatial arrangement of contacts around the ring-shaped well into a temporal sequence by sequentially activating contacts in angular order. This converts the spatial dimension of magnetic field direction measurement into the time dimension, where the phase of the output signal directly corresponds to the magnetic field direction, eliminating the need for complex mathematical calculations.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent introduces dynamic sequential activation of contacts around the ring-shaped well, where contacts are activated one after another in angular order. This dynamic approach transforms the static spatial information into a dynamic temporal signal, where the timing and phase of the output signal directly indicate the magnetic field direction.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If complex mathematical calculations are performed to derive magnetic field direction, then accurate measurement is achieved, but processing time and computational resources increase

Engineering Contradiction:
Improvemagnetic field direction accuracyVSAvoidsignal processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the computational system (mathematical calculations) with a direct physical measurement system. The phase of the output signal directly represents the magnetic field direction, allowing for instantaneous determination without requiring computational processing, thus eliminating the time loss associated with mathematical calculations.

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

3Loss of information

If multiple contacts are arranged around a ring-shaped well, then spatial information is captured, but the device structure becomes more complex

Engineering Contradiction:
Improvespatial information captureVSAvoidsensing structure complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent makes the single vertical Hall element multi-functional by sequentially connecting it to multiple contacts around the ring-shaped well. This single Hall element serves multiple measurement positions in sequence, capturing spatial information from all contacts without requiring multiple physical Hall elements, thus reducing device complexity while maintaining full spatial information capture capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables direct and efficient measurement of the magnetic field direction without requiring intricate mathematical processing, simplifying the data interpretation and improving accuracy.

Implementation Method 1

A magnetic field sensor uses a sensing structure that measures the spatial information on the direction of the in-plane magnetic field B. The electronic circuit operates the sensing structure in such a way that this information is transformed into a time signal. The sensing structure comprises a ring-shaped, electrically conductive well and a plurality of at least eight contacts of equal size placed at equal distance from each other along the ring-shaped well and contacting the ring-shaped well.

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP2153241B1Magnetic field sensor for measuring direction of a magnetic field in a plane
Publication Date: 2013.03.13 ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)
  • EP2153241B1 patent drawingFigure 1~3
  • EP2153241B1 patent drawingFigure 4~5
  • EP2153241B1 patent drawingFigure 6

AI summary

A magnetic field sensor for measuring a direction of a magnetic field in a plane comprises a sensing structure (4) comprising a ring-shaped well (10), a plurality of contacts (11) of equal size placed at equal distance from each other along the ring-shaped well, and an electronic circuit (5) comprising a plurality of electronic switches (12) associated with the contacts (11) of the sensing structure (4), a logic block (18) for controlling the electronic switches (12), at least one current source (13; 14), a means for measuring a difference between a first voltage and a second voltage, a timing circuit providing a control signal for controlling the logic block (18) and providing a reference signal, wherein the logic block is adapted to close and open the electronic switches under the control of the control signal according to a predetermined scheme such that a predetermined number of contacts of the plurality of contacts form a vertical Hall element that is supplied with current from the at least one current source and that has two contacts connected to the means for measuring, and such that the vertical Hall element is moved in steps along the ring-shaped well, and a means for measuring a phase shift between the reference signal and an output signal of the voltage measuring means.