Adjustable Noise Filter Magnetic Core for Inductance Cancellation

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Solution Overview

Problem

Existing noise filters struggle to effectively suppress high-frequency components of electromagnetic noise due to manufacturing tolerances, requiring re-design and re-manufacturing of printed circuit boards to achieve optimal performance.

Innovation Solution

A noise filter configuration that includes a magnetic core with a distance adjusting member to optimize the distance between loop-shaped conductor wiring lines and the magnetic core, allowing for adjustment to cancel out inductance components and enhance noise suppression without re-designing or re-manufacturing the board.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If reactors are selected to cancel inductance components based on design values, then high-frequency noise suppression is improved, but manufacturing tolerances cause the inductance cancellation to be insufficient, requiring re-design and re-manufacturing

Engineering Contradiction:

Improvenoise suppression effectivenessVSAvoidinductance cancellation accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent makes the magnetic core position adjustable rather than fixed, allowing the mutual inductance to be dynamically tuned after manufacturing. The distance adjusting member enables the magnetic core to be repositioned to optimize inductance cancellation based on actual manufacturing variations, resolving the contradiction between design-stage inductance selection and manufacturing tolerance-induced deviations.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of mutual inductance by adjusting the distance between the magnetic core and the conductor wiring lines. By modifying this physical parameter after manufacturing, the system can compensate for inductance mismatch caused by manufacturing tolerances, thereby maintaining effective high-frequency noise suppression without requiring re-design or re-manufacturing.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If the distance between loop portions and magnetic core is fixed during manufacturing, then production is simplified, but optimal noise suppression cannot be achieved due to tolerance variations

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidnoise suppression performance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces a distance adjusting member that transforms the fixed distance into an adjustable parameter. This allows the manufacturing process to remain simple with a standard fixed-position magnetic core, while enabling post-manufacturing adjustment to optimize noise suppression performance, thus resolving the contradiction between manufacturing simplicity and performance reliability.

Inventive Principle:

Principle #15Dynamics

3Object-affected harmful factors

If inductance components are not properly cancelled, then high-frequency noise propagates, but re-design and re-manufacturing of the board is required to fix the issue

Engineering Contradiction:

Improvehigh-frequency noise propagationVSAvoidre-design and re-manufacturing time

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The patent incorporates a distance adjusting member during the initial manufacturing stage, enabling preliminary adjustment of the magnetic core position to achieve proper inductance cancellation. This preliminary action prevents the need for time-consuming re-design and re-manufacturing processes later, as the system can be tuned to optimal performance during first-time production.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The distance adjusting member enables the noise filter system to self-adjust and self-optimize its performance. Rather than requiring external re-design and re-manufacturing interventions, the system provides its own adjustment capability, allowing operators to tune the magnetic core position to achieve proper inductance cancellation and eliminate high-frequency noise propagation.

Inventive Principle:

Principle #25Self-service

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 increases the effectiveness of suppressing high-frequency electromagnetic noise by adjusting the mutual inductance between loop portions, ensuring optimal noise suppression without the need for re-design or re-manufacturing of the printed circuit board.

Implementation Method 1

the second conductor wiring line being coupled to the first conductor wiring line by a magnetic field

Methodology Applied

Scientific EffectMagnetic field coupling: Magnetic Field

Implementation Method 2

the first reactor and the second reactor are coupled to each other by a magnetic field with a mutual inductance M. The mutual inductance M acts to reduce the inductance components included in the capacitor, etc.

Methodology Applied

Scientific EffectMutual inductance: Electromagnetic Induction

Data Source

PatentUS11381213B2Noise filter and electrical and electronic equipment

Publication Date: 2022.07.05 MITSUBISHI ELECTRIC CORP

AI summary

A noise filter includes a magnetic core including a magnetic material; and a distance adjusting member that accepts adjustment of a distance between a loop portion and the magnetic core, the loop portion being a portion of one or more conductor wiring lines wired in loop shape out of a first conductor wiring line and a second conductor wiring line.