Current-Compensated Choke with Alternating Windings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing chokes fail to completely eliminate magnetic fields and minimize resistance, which is crucial for applications like data bus systems where low resistance and reduced leakage inductance are necessary.

Innovation Solution

A current-compensated choke design with multiple windings arranged in parallel on a common core, where windings are wound in a specific alternating pattern to cancel out magnetic fields, and a cap or cover plate is used to enhance magnetic closure, reducing leakage inductance and ohmic resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If multiple windings are connected in parallel to reduce resistance, then resistance decreases, but magnetic field cancellation becomes more difficult to achieve completely

Engineering Contradiction:
ImproveresistanceVSAvoidmagnetic field cancellation
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The choke is divided into multiple current paths (at least two), each with its own windings connected in parallel. This segmentation allows independent optimization of each current path while maintaining overall low resistance and enabling complete magnetic field cancellation through proper arrangement of the segmented windings.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Windings belonging to different current paths are arranged asymmetrically around the core, specifically positioned so that their magnetic fields oppose and cancel each other. This asymmetric arrangement is crucial for achieving complete magnetic field cancellation while maintaining low resistance through parallel connections.

Inventive Principle:
Principle #4Asymmetry

2Object-generated harmful factors

If windings are arranged to cancel magnetic fields, then leakage inductance decreases, but resistance increases

Engineering Contradiction:
Improveleakage inductanceVSAvoidresistance
Core Design Contradiction:
Object-generated harmful factorsVSLoss of energy

Solution Approach 1:

By segmenting the choke into multiple current paths with parallel windings, the design achieves low resistance through the parallel connection while maintaining effective magnetic field cancellation that reduces leakage inductance. Each current path contributes to both low resistance and magnetic field cancellation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple windings are merged into parallel connections to form common current paths. This merging reduces the overall resistance while the combined magnetic fields of the parallel windings are arranged to cancel each other, simultaneously achieving low resistance and reduced leakage inductance.

Inventive Principle:
Principle #5Merging (Combining)

3Object-generated harmful factors

If windings are arranged in alternating pattern for magnetic field cancellation, then leakage inductance is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improveleakage inductanceVSAvoidwinding arrangement
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The winding structure is segmented into distinct current paths with specific arrangement patterns. This segmentation provides a systematic approach to achieving magnetic field cancellation, making the complex winding arrangement more manageable and manufacturable through clear structural organization.

Inventive Principle:
Principle #1Segmentation

4Object-generated harmful factors

If a cap or cover plate is added to improve magnetic closure, then leakage inductance decreases, but device complexity increases

Engineering Contradiction:
Improveleakage inductanceVSAvoidstructure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The cap or cover plate is extracted as a separate, optional component that can be added to improve magnetic closure. This allows the basic choke structure to remain simple while providing the option to reduce leakage inductance further through the addition of this external magnetic shielding element.

Inventive Principle:
Principle #2Taking out (Extraction)

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 design achieves minimal stray inductance and equal resistance across current paths, effectively addressing the need for low leakage inductance and resistance in data bus systems, such as CAN or FlexRay bus systems, by canceling out magnetic fields and optimizing the choke's structure.

Implementation Method 1

at least two windings arranged on a common core, through which the current can flow in such a way that their magnetic fields cancel each other out

Methodology Applied
Scientific EffectMagnetic field cancellation: Magnetic Field

Implementation Method 2

the windings on the core are largely surrounded by a cap. This leads to a further reduction in leakage inductance

Methodology Applied
Scientific EffectMagnetic closure: Magnetic Field

Implementation Method 3

By connecting several windings in parallel to form a common current path, low resistance values can be achieved

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP2171732B1Current-compensated choke and circuit arrangement having a current-compensated choke
Publication Date: 2017.09.06 TDK ELECTRONICS AG
  • EP2171732B1 patent drawingFigure 1
  • EP2171732B1 patent drawingFigure 2~3

AI summary

The invention relates to a current-compensated choke, comprising a plurality of current paths (1, 2) and being made of a plurality of windings (1a, 1b, 2a, 2b) that are connected in parallel and are wound around a common core (3). The windings (1a, 1b, 2a, 2b) are preferably wound around the core (3) in an alternating way such that windings (1a, 1b, 2a, 2b) of a common current path (1, 2) are not arranged directly on top of each other.