Flat Cable Line Filter Noise Reduction via Nested Core Winding
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Solution Overview
Problem
Existing line filters are insufficient in reducing unnecessary noise radiation by flat cables, and increasing the core width or number of cores to enhance noise reduction increases costs and complexity.
Innovation Solution
A line filter design that passes a flat cable through a ferrite core twice, with alternating penetration and connection portions, allowing the cable to be wound around the core, reducing noise radiation without increasing core width, and optionally passing the cable through the core three times for further noise reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the core width is increased or the number of cores is increased to reduce noise radiation, then the noise reduction effect is improved, but the cost and device complexity increase
Solution Approach 1:
The cable is passed through the same core multiple times (first penetrating portion and second penetrating portion) in a nested manner, allowing the cable to wind around the core and increase the effective interaction length with the ferrite material without requiring additional cores or increasing core width, thereby reducing noise while maintaining compact dimensions
Solution Approach 2:
Instead of increasing noise reduction by adding more cores in the lateral dimension (increasing width), the invention utilizes the longitudinal dimension by passing the cable through the core multiple times and winding it around, effectively increasing the noise reduction path length without expanding the core width
2Object-affected harmful factors
If the cable is wound to the core to reduce noise radiation, then the noise reduction effect is improved, but the core width must be about two times larger
Solution Approach 1:
The cable is passed through the core in a nested sequence (first penetrating portion, then second penetrating portion) and wound around the core, maximizing the use of the existing core volume and achieving effective noise reduction without requiring doubled core width
Solution Approach 2:
The invention transitions from a single-pass linear configuration to a multi-pass wound configuration, utilizing the vertical and lateral dimensions of the existing core to create an extended noise reduction path without increasing the overall core width
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 effectively reduces noise radiation to a level equivalent to using two cores without increasing the core width, thereby minimizing cost and complexity while maintaining noise reduction efficacy.
Implementation Method 1
A problem of electromagnet interference (EMI) arises which is unnecessary noise radiation by the cable when electric current flows in the cable. In order to reduce the unnecessary noise radiation by the cable, a line filter has been used.
Implementation Method 2
A line filter 100 according to one example of the present disclosure will be described with reference to FIG. 1. The line filter 100 includes a core 10 and a cable 20. The line filter 100 reduces unnecessary noise radiation by the cable 20 in a manner that the cable 20 is passed through the core 10.
Data Source
Figure 1
Figure 2A~2D
Figure 3
AI summary
A line filter (100) includes a flat plate-shaped cable (20) and a flat core (10). A through hole (11) having a shape corresponding to the cable (20) is formed in the core (10). The cable (20) includes: a first penetrating portion (21) which enters the through hole (11) in the core (10) from an inlet (12) of the through hole (11) and is passed through an outlet (13) of the through hole (11); a second penetrating portion (22) which enters the through hole (11) in the core (10) from the inlet (12) of the through hole (11) and is passed through the outlet (13) of the through hole (11); and a first connecting portion (30) which connects the first penetrating portion (21) on a side of the outlet (13) of the through hole (11) to the second penetrating portion (22) on a side of the inlet (12) of the through hole (11) not through the through hole (11). When viewed in a normal direction of a main surface of the core (10), the second penetrating portion (22) overlaps with the first penetrating portion (21) at least partially.