Busbar Filter Module Layout for Differential and Common Mode Noise

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Solution Overview

Problem

Existing filter modules for reducing differential and common mode electrical noise are costly and complex to manufacture, often requiring additional material and space due to the design of ferrite cores and precise positioning of busbars.

Innovation Solution

A filter module design featuring preassembled circuit boards with bypass capacitors between common mode chokes, using ferrite cores that create single turn inductors to suppress noise, and spring contacts for electrical connections, which simplifies manufacturing and reduces material costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dual mode choke with ferrite cores is used to suppress both differential and common mode noise, then noise suppression capability is improved, but weight and material costs increase

Engineering Contradiction:

Improvenoise suppression capabilityVSAvoidweight

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The filter module is divided into separate functional sections: common mode chokes for common mode noise suppression, bypass capacitors for differential mode noise suppression, and a circuit board for signal routing. This segmentation allows each component to be optimized independently, reducing the need for heavy dual-mode ferrite cores while maintaining overall noise suppression effectiveness.

Inventive Principle:

Principle #1Segmentation

2Reliability

If dual mode choke with ferrite cores is used to suppress both differential and common mode noise, then noise suppression capability is improved, but material costs increase

Engineering Contradiction:

Improvenoise suppression capabilityVSAvoidmaterial costs

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The circuit board serves multiple functions: it provides mechanical support for components, routes electrical signals between busbars and external connections, and hosts bypass capacitors for differential mode filtering. This multi-functionality reduces the need for additional specialized components, lowering material costs.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If ferrite cores are designed to create single turn inductor with busbars, then common mode noise suppression is improved, but space requirement increases

Engineering Contradiction:

Improvecommon mode noise suppressionVSAvoidspace requirement

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The busbars are configured in a three-dimensional arrangement where they extend through the ferrite cores in specific orientations. This spatial arrangement allows the ferrite cores to effectively suppress common mode noise while minimizing the overall footprint of the filter module on the circuit board.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

4Reliability

If busbars are embedded in common mode choke, then noise suppression is improved, but manufacturing complexity and cost increase

Engineering Contradiction:

Improvenoise suppressionVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The ferrite cores are pre-assembled onto the busbars before final installation into the filter module. This preliminary assembly simplifies the manufacturing process by allowing the cores to be attached to the busbars in a separate, more accessible setup, rather than requiring complex embedding operations during final assembly.

Inventive Principle:

Principle #10Preliminary 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 results in a more cost-effective and simpler filter module that effectively reduces both differential and common mode noise while minimizing space and material requirements, with improved thermal insulation and assembly efficiency.

Implementation Method 1

The first ferrite core creates a single turn inductor with respect to the first busbar and the second busbar in order to suppress common mode noise

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The filter module comprises at least a first bypass capacitor which is electrically connected to the first busbar and the second busbar

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS11849537B2Filter module for reducing differential and common mode noise and method to manufacture such a filter module

Publication Date: 2023.12.19 MAHLE INT GMBH

AI summary

A filter module for reducing differential and common mode electrical noise may include at least a first electrically conductive busbar and a second electrically conductive busbar spaced apart from the first busbar, an at least partially electrically conductive housing at least partially enclosing the first busbar and the second busbar, at least a first common mode choke and a second common mode choke arranged in the housing and spaced apart from each other, at least a first bypass capacitor electrically connected to the first busbar and the second bus bar, at least a second bypass capacitor electrically connected to the first busbar and a midpoint, and at least a third bypass capacitor electrically connected to the second busbar and the midpoint.