Variable Inductor Using Magnetic Powder for Fast Flux Control

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Solution Overview

Problem

Existing variable inductors face stability and energy efficiency issues due to the need for mechanical movement of a movable core and continuous current control, which results in low operation speed and high power consumption.

Innovation Solution

A variable inductor design utilizing a receptacle portion with magnetic powder that moves within a space defined by different magnetic field regions, allowing for changes in inductance value through magnetic flux variations, and an electric field generating electrode to control the powder's movement with reduced energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a movable core is mechanically moved to block magnetic flux, then the inductance value can be varied, but the operation stability deteriorates and the reaction speed becomes slow due to the large mass of the movable core

Engineering Contradiction:

Improveinductance value variationVSAvoidoperation stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent replaces the mechanical movable core system with a magnetic powder system that can be controlled by electric fields. Instead of mechanically moving a heavy core to block magnetic flux, the invention uses electrically controllable magnetic powder particles that can be positioned and held in place without mechanical actuators, thereby eliminating the stability and speed issues associated with mechanical movement of heavy components

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the control parameter from mechanical position to electric field strength. By applying different electric field strengths to the magnetic powder, the inductance value can be varied continuously without mechanical movement. The magnetic powder's position and density distribution are controlled by electric field parameters rather than mechanical displacement

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If a movable core is mechanically moved to block magnetic flux, then the inductance value can be varied, but the energy consumption increases due to the large mass requiring more power to move

Engineering Contradiction:

Improveinductance value variationVSAvoidpower consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces electric field as an intermediary to control the magnetic powder. Rather than directly applying mechanical force to move the magnetic material, an electric field is used as a mediator to manipulate the magnetic powder's position and distribution, which in turn controls the magnetic flux and inductance value with minimal energy expenditure

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If continuous current control is applied to vary inductance, then the inductance value can be adjusted, but the power efficiency deteriorates due to wasted DC current component

Engineering Contradiction:

Improveinductance value adjustmentVSAvoidpower efficiency

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent uses periodic or pulsed electric field application instead of continuous current control. By applying electric field pulses to move and position the magnetic powder only when needed for inductance adjustment, the system eliminates the continuous power consumption associated with maintaining DC current, thereby improving power efficiency while retaining inductance adjustment capability

Inventive Principle:

Principle #19Periodic action

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 design achieves stable and quick inductance value variation with lower energy requirements, enhancing operation stability and reaction speed while minimizing power consumption.

Implementation Method 1

at least one coil that produces a magnetic flux

Methodology Applied

Scientific EffectMagnetic flux: Magnetic Field

Implementation Method 2

the space defined by the receptacle portion include a first region in which a magnetic field provided by the at least one coil is relatively strong and a second region in which the magnetic field is relatively weak and that the magnetic powder can move between the first region and the second region

Methodology Applied

Scientific EffectMagnetic field force: Magnetic Field

Implementation Method 3

the variable inductor further includes an electric field generating electrode for applying a voltage so as to generate an electric field within the space, and the magnetic powder is moved within the space by applying a voltage to the electric field generating electrode

Methodology Applied

Scientific EffectElectric field: Electric Field

Data Source

PatentUS11043323B2Variable inductor

Publication Date: 2021.06.22 MURATA MFG CO LTD

AI summary

First and second coils are disposed coaxially with a gap provided therebetween and are configured to mutually cancel out magnetic fields provided thereby. A receptacle portion that defines a space traversing at least a portion of a magnetic flux produced by the coils is provided, and a magnetic powder is contained in the receptacle portion so as to occupy a portion of the space. The magnetic powder moves within the space, and this movement produces a change in the magnetic flux. This change in the magnetic flux appears in the form of a change in the inductance value.