High-Current Choke with Symmetrical Coils on Common Core

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High-current-resistant radio interference suppression chokes face issues with magnetic saturation and high space requirements, leading to increased material costs and impaired damping at high current levels due to asymmetrical coil arrangements and large core sizes.

Innovation Solution

The use of a highly permeable core with two coils wound over the same circumference, where electrical conductors are parallel and untwisted, distributed evenly, and wound in multiple layers to achieve symmetry and reduce leakage inductance, allowing for compact design and low production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the core is divided into two separate sections with single coils on each section, then the damping is adequate, but the space requirement and material costs increase due to large core dimensions

Engineering Contradiction:
Improvedamping performanceVSAvoidcore volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent merges the two separate coil sections into a single continuous coil arrangement around the core. The first and second coils are wound adjacently on the same core section, sharing a common magnetic path, which reduces the required core volume while maintaining the damping effect through the combined winding structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from a distributed spatial arrangement (two separate coils on separate core sections) to a concentrated arrangement (two coils on the same core section). This dimensional reorganization allows the magnetic fields to interact more efficiently within a compact volume, achieving adequate damping without increasing core size.

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

2Device complexity

If asymmetrical coil arrangement is used, then the structure is simpler, but magnetic saturation occurs at high current levels

Engineering Contradiction:
Improvecoil arrangement complexityVSAvoidmagnetic saturation resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent deliberately introduces asymmetry in the form of an air gap in the core to compensate for the asymmetrical placement of coils. This air gap prevents magnetic saturation by providing a controlled magnetic reluctance that linearizes the magnetic circuit, allowing the asymmetrical coil arrangement to function reliably at high current levels.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent changes the magnetic circuit parameters by introducing an air gap, which fundamentally alters the magnetic saturation characteristics. This parameter modification allows the system to handle high current levels without saturation, even with the simplified asymmetrical coil arrangement.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If large core size is used to avoid magnetic saturation, then the damping performance is maintained, but the space requirement and production costs increase

Engineering Contradiction:
Improvedamping performanceVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines multiple functional elements (two coils, magnetic damping, current handling) into a single integrated structure where the first and second coils are wound on the same core section. This merging eliminates the need for oversized cores while maintaining damping performance, thereby reducing material costs and simplifying manufacturing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent modifies the magnetic circuit parameters through the air gap design, which allows compact core dimensions to achieve the same damping performance that would otherwise require larger cores. This parameter optimization reduces material usage and production costs while maintaining reliability.

Inventive Principle:
Principle #35Parameter changes

4Device complexity

If coils are wound over less than half the circumference of the core, then the structure is simpler, but magnetic saturation occurs particularly at high current levels

Engineering Contradiction:
Improvecoil winding complexityVSAvoidhigh current resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent concentrates the coil windings in a specific local region of the core (adjacent sections) rather than distributing them uniformly. This local concentration, combined with the air gap, creates a focused magnetic path that handles high currents effectively without requiring the coils to extend over more than half the core circumference.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The introduction of an air gap fundamentally changes the magnetic circuit parameters, allowing the coil arrangement to handle high current levels without saturation. This parameter change enables the simplified coil configuration to achieve high current resistance that would otherwise require more extensive winding coverage.

Inventive Principle:
Principle #35Parameter changes

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 prevents core saturation at high currents, achieves high impedance and damping, and reduces production costs by utilizing the core circumference efficiently, while allowing for adjustable damping properties and effective heat dissipation through hollow conductors.

Implementation Method 1

the core is made of a highly permeable material

Methodology Applied
Scientific EffectMagnetic permeability: Ferromagnetism

Implementation Method 2

electrical conductors that form the coils and are routed in a filter circuit for conducting currents of one hundred amperes or more

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

The symmetry of the windings avoids partial saturation of the core at high currents

Methodology Applied
Scientific EffectMagnetic saturation: Magnetic Saturation

Implementation Method 4

The symmetry of the windings avoids partial saturation of the core at high currents. Thanks to the invention, a high impedance can be achieved over the frequency in direct current applications and thus damping in the so-called common mode

Methodology Applied
Scientific EffectMagnetic field distribution: Magnetic Field

Data Source

PatentEP2495742B1High-voltage resistant electricity-compensated interference suppression choke
Publication Date: 2016.03.30 SEKELS
  • EP2495742B1 patent drawingFigure 1~3
  • EP2495742B1 patent drawingFigure 4~5
  • EP2495742B1 patent drawingFigure 6~7

AI summary

The inductor (3) has closed core (4) which are wound with coils (5,6). The coils with commutative electric conductors (a,b) form a filter circuit. The coils are wound over the same portion (7) of the periphery of the core.