Compact EMI Filter Module Using Segmented Magnetic Cores
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Solution Overview
Problem
The increasing power consumption and size of EMI filters in electronic circuits pose a challenge, as traditional toroid chokes become too large when currents exceed 10A, necessitating a reduction in filter size without increasing board space.
Innovation Solution
A power source interface module with a compact design featuring stacked circuit board layers, magnetically coupled inductive coils with a core having two legs that stretch through openings, and a magnetic core with yokes to increase leakage inductance, allowing for more efficient differential mode filtering and reduced size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional toroid chokes are used for EMI filtering, then filtering performance is achieved, but the filter size becomes too large when currents exceed 10A
Solution Approach 1:
The patent divides the traditional single toroid choke into two separate E-shaped magnetic cores with interleaved windings. This segmentation allows the magnetic paths to be separated while maintaining the required inductance and filtering performance, significantly reducing the overall filter size for currents exceeding 10A
Solution Approach 2:
The patent implements a nested winding structure where the first and second windings are interleaved between the two E-shaped cores. The windings are positioned such that they share the same spatial envelope, with each winding nested within the magnetic structure of the other, maximizing space utilization and reducing filter volume
2Power
If power consumption increases, then more power handling capability is achieved, but the EMI filter size increases
Solution Approach 1:
The patent changes the magnetic circuit parameters by using two E-shaped cores with specific leg configurations and interleaved windings. This parameter optimization allows the filter to handle higher power levels while maintaining a compact size, as the magnetic flux paths are efficiently distributed across the two cores rather than concentrated in a single large toroid
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 reduces the size and height of the power source interface module while maintaining the required number of coil turns, improving differential mode filtering and allowing for increased power handling without additional board space.
Implementation Method 1
at least one pair of magnetically coupled inductive coils
Implementation Method 2
a magnetic core with yokes to increase leakage inductance
Data Source
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AI summary
The invention is directed towards a power source interface module for electronic circuits supplied by power from a power source as well as a power supply arrangement for electronic circuits comprising such a power source interface module. The module comprises a first circuit board (22) carrying components, the first circuit board (22) comprising a number of stacked circuit board layers as well as at least two openings (32, 34, 36, 37), at least a part of a filter comprising at least one pair of magnetically coupled inductive coils, a core with two core legs, each core leg stretching through a corresponding opening (32, 34) in the circuit board (22), wherein each coil is wound around a corresponding core leg, the turns of the coils stretch through the circuit board layers, and each layer between an upper outer layer and a lower outer layer comprises at least a part (24, 26, 28, 30) of one turn.