Laminated Common Mode Choke Coil Orthogonal Axis Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing common mode choke coils face issues with positional symmetry and coupling with ground conductors on printed wiring boards, leading to increased loss of normal mode signals and reduced removability of common mode noise, especially in high frequency bands.
Innovation Solution
A laminated common mode choke coil design with primary and secondary coils connected in series, where the first and third coil elements are wound around one axis and the second and fourth coil elements around a different axis, ensuring adjacent placement in the orthogonal direction, generating a magnetic field in the same direction for common mode current, thus enhancing coupling and reducing normal mode signal loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the primary coil and secondary coil are arranged symmetrically in the lamination direction, then the common mode noise removability is improved, but manufacturing precision deteriorates due to positional shifts and stacking errors
Solution Approach 1:
The patent applies asymmetry by changing from a symmetric arrangement (both coils wound around the same axis) to an asymmetric arrangement (coils wound around different axes). Specifically, the primary coil is wound around a first axis and the secondary coil is wound around a second axis that is orthogonal to the first axis, eliminating the need for precise symmetry while maintaining functional effectiveness.
Solution Approach 2:
The patent transitions from a one-dimensional symmetric arrangement (coils stacked along the lamination direction) to a three-dimensional asymmetric arrangement by winding coils around different orthogonal axes. This dimensional change allows the coils to be positioned in space without requiring precise alignment in the lamination direction, thereby reducing manufacturing complexity.
2Reliability
If magnetic material is used as the laminated element body, then the common mode choke performance is improved, but normal mode signal loss increases particularly in high frequency bands
Solution Approach 1:
The patent applies local quality by using magnetic material only in specific regions where it is most beneficial for common mode noise suppression, rather than uniformly throughout the entire structure. The magnetic material is strategically placed to enhance common mode choke performance while minimizing its impact on normal mode signals.
Solution Approach 2:
The patent employs composite materials by combining magnetic material with non-magnetic materials in the laminated element body. This composite structure allows the magnetic material to provide common mode choke performance while the non-magnetic materials minimize losses in high frequency bands, achieving a balance between the two requirements.
3Device complexity
If the coils are wound around the same axis, then the structure is simplified, but coupling between coils deteriorates in high frequency bands
Solution Approach 1:
The patent uses dimensional change by winding the primary coil around a first axis and the secondary coil around a second axis that is orthogonal to the first axis. This three-dimensional arrangement improves magnetic coupling between the coils by creating overlapping magnetic fields, while the winding structures remain relatively simple and manufacturable.
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 ensures excellent symmetry and increased coupling between coils, resulting in reduced impedance for common mode noise and minimal loss for normal mode signals, achieving a small-sized choke coil with high removability of common mode noise.
Implementation Method 1
the first coil element, the second coil element, the third coil element and the fourth coil element are connected in such a manner that a magnetic field in the same direction is generated in the first coil element, the second coil element, the third coil element and the fourth coil element when common mode current flows
Data Source
AI summary
A primary coil is configured by series connection of a first coil element (L1a), a second coil element (L1b) and a fifth coil element (L1c), and a secondary coil is configured by series connection of a third coil element (L2a), a fourth coil element (L2b) and a sixth coil element (L2c). The coil elements (L1a, L2b, L1c) are disposed coaxially and the coil elements (L2a, L1b, L2c) are also disposed coaxially. The respective coil elements (L1a, L1b, L1c) of the primary coil and the respective coil elements (L2a, L2b, L2c) of the secondary coil are disposed adjacently in a layer direction of a base material layer, respectively. The coil elements (L1a, L1b, L1c, L2a, L2b, L2c) are connected in such a manner that a magnetic field in the same direction is generated in all of the coil elements (L1a, L1b, L1c, L2a, L2b, L2c) when common mode current flows.