Gap-Magnetized Energy Transfer Element for Stable Flux Offset
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional energy transfer elements in switched mode power supplies face challenges with power loss due to eddy currents in permanent magnets and variability in flux density offset, making them impractical for mass production.
Innovation Solution
An energy transfer element with a magnetic core having a gap, where magnetizable material, such as Neodymium Iron Boron or Samarium Cobalt, is introduced in the gap and magnetized to provide a flux density offset, reducing power loss and improving manufacturing feasibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a permanent magnet is inserted into the air gap to provide flux density offset, then the flux density offset is provided, but power loss due to eddy currents increases and manufacturing variability increases
Solution Approach 1:
The patent changes the magnetic state of the material from permanently magnetized to temporarily magnetized on-demand. By using magnetizable material without permanent magnetization and applying external magnetic fields through windings to create the required flux density offset only when needed, the invention eliminates continuous power loss from eddy currents while maintaining flux density offset stability.
Solution Approach 2:
The magnetizable material in the gap serves itself by being magnetized through the existing power windings rather than requiring a separate permanent magnet. The material responds to the magnetic fields generated by the windings, providing flux density offset without needing continuous external energy input or permanent magnetization.
2Reliability
If a permanent magnet is inserted into the air gap to provide flux density offset, then the flux density offset is provided, but manufacturing precision and tolerances become problematic
Solution Approach 1:
The patent eliminates the need for precisely controlled permanent magnet thickness by using magnetizable material that can be magnetized to any required strength through controlled application of magnetic fields from the windings. This transforms the manufacturing challenge from mechanical dimensioning to electrical parameter control, which is more easily managed.
Solution Approach 2:
The patent replaces the mechanical approach of using a physically dimensioned permanent magnet with an electrical approach using magnetizable material and controlled magnetic fields. Instead of relying on mechanical tolerances for magnet thickness, the flux density offset is controlled through electrical parameters (current, turns ratio) of the windings.
3Loss of energy
If magnetizable material is magnetized to provide flux density offset, then power loss is reduced, but additional manufacturing steps are required
Solution Approach 1:
The patent combines the flux density offset function with the existing power windings by using the same windings to create the magnetic fields that magnetize the gap material. This merging eliminates the need for separate permanent magnets and their associated manufacturing, assembly, and positioning steps, simplifying the overall manufacturing process despite the magnetization requirement.
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 solution effectively reduces power loss and enhances the manufacturing efficiency of energy transfer elements by stabilizing the flux density offset, enabling more efficient energy transfer and cost-effective production.
Implementation Method 1
Magnetizable material producing an initial flux density is positioned in the gap. When the magnetizable material is magnetized the flux density produced by the magnetized material is offset from the initial flux density.
Implementation Method 2
However, due to the changing magnetic fields of an energy transfer element, the permanent magnet may be susceptible to eddy currents. The eddy current can produce an undesirable power dissipation in the magnet.
Data Source
AI summary
An energy transfer element comprises a magnetic core having a gap in a magnetic path. Magnetizable material producing an initial flux density is positioned in the gap. One or more power windings is wrapped around the magnetic path. When the magnetizable material is magnetized the flux density produced by the magnetized material is offset from the initial flux density. The core is a toroid magnetic core or is comprised of two core pieces. The magnetizable material is an unmagnetized magnet or a mixture of a suspension medium comprising uncured epoxy and magnetizable particles. The magnetizable particles are selected from a group comprising Neodymium Iron Boron (NdFeB) based materials or Samarium Cobalt (SmCo) based material.