Parallel Current Sensor Units for Magnetic Interference Suppression

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Solution Overview

Problem

Current sensors face challenges in size reduction due to increased measurement errors caused by external magnetic fields and magnetic fields circling around adjacent conductors, which are not effectively suppressed by existing designs.

Innovation Solution

The design incorporates a current sensor unit with a plate-shaped conductor and magnetic sensor elements that divide the current flow into arch-shaped and inverted arch-shaped portions, positioned parallel to each other with a space in between, and a slit in the middle, allowing the magnetic sensor elements to detect the magnetic field generated by the current while minimizing the influence of external and adjacent magnetic fields.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the distance between adjacent current paths is decreased to reduce sensor size, then the compactness of the current sensor is improved, but the measurement precision deteriorates due to increased magnetic field interference from adjacent conductors

Engineering Contradiction:

Improvesensor sizeVSAvoidcurrent measurement accuracy

Core Design Contradiction:

Volume of moving objectVSMeasurement precision

Solution Approach 1:

The patent converts the harmful magnetic field from adjacent conductors into a beneficial signal by strategically positioning magnetic sensor elements to detect both the target conductor's field and the adjacent conductor's field. Through differential measurement, the system extracts the target current information while eliminating the interference, thus transforming the harmful magnetic interference into a useful measurement mechanism

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces magnetic sensor elements as intermediary devices positioned between the conductors and the measurement system. These sensor elements detect magnetic fields from multiple conductors and transfer the combined information to the calculation unit, which then processes the signals to isolate the target current, effectively using the magnetic sensor elements as mediators to manage the magnetic field interference

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If conductor units are bent in a single plane to suppress magnetic field influence on magneto-electro transducers, then the measurement precision is improved, but the area occupied by current paths increases, worsening the compactness

Engineering Contradiction:

Improvemagnetic field interference suppressionVSAvoidplanar space occupied by current paths

Core Design Contradiction:

Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent transitions from two-dimensional planar arrangement to three-dimensional spatial configuration by positioning magnetic sensor elements at different heights (above or below) the conductor plane. This vertical dimension allows the sensor elements to detect magnetic fields while maintaining compact planar footprint, effectively resolving the conflict between interference suppression and compactness

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent segments the magnetic field detection function by placing multiple magnetic sensor elements at different positions (above and below conductors) rather than using a single detection plane. This segmentation allows selective detection of magnetic field components and enables compact routing of current paths without compromising interference suppression

Inventive Principle:

Principle #1Segmentation

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 configuration reduces measurement errors and enables a more compact current sensor by effectively suppressing external and adjacent magnetic field influences, allowing for accurate current measurement without the need for conductor bending in a single plane.

Implementation Method 1

The first magnetic sensor element and the second magnetic sensor element detect strength of a magnetic field generated by the current

Methodology Applied

Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentUS10274523B2Current sensor including a first current sensor and a second current sensor unit

Publication Date: 2019.04.30 MURATA MFG CO LTD

AI summary

A current sensor including first and second current sensor units. Conductors of the first and second current sensor units extend in a length direction and are parallel or substantially parallel to each other with a space therebetween. An arch-shaped portion and an inverted arch-shaped portion of the first current sensor unit are at different positions in the length direction from positions of an arch-shaped portion and an inverted arch-shaped portion of the second current sensor unit. When seen in a width direction perpendicular or substantially perpendicular to the length direction, first and second magnetic sensor elements of the first current sensor unit are outside an opening of the second current sensor unit and first and second magnetic sensor elements of the second current sensor unit are outside an opening of the first current sensor unit.