Shielding Winding Reduces Conductivity EMI in Energy Transfer Apparatus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing energy transfer apparatuses in power supplies face challenges in reducing conductivity electromagnetic interference (EMI) due to high switching frequencies, leading to increased costs and potential damage from additional shielding components or windings that occupy valuable space.
Innovation Solution
The apparatus employs a shielding winding and an auxiliary winding capacitively coupled to the input and output windings, respectively, to stabilize electric potential and reduce EMI without the need for additional shielding capacitors or copper foils, using a manufacturing method that optimizes winding placement and turns to minimize space and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a shielding capacitor is placed between input and output ground terminals to reduce conductivity EMI, then EMI reduction is achieved, but safety deteriorates due to leakage current and cost increases
Solution Approach 1:
The patent extracts the harmful parasitic capacitor effect by introducing a shielding winding that generates a counteracting magnetic field, eliminating the need for shielding capacitors and their associated safety and cost problems
2Object-affected harmful factors
If a copper foil shielding layer is installed between input and output windings to reduce conductivity EMI, then EMI reduction is achieved, but device complexity and space requirements increase
Solution Approach 1:
The patent merges the shielding function into the existing winding structure by adding a shielding winding that serves both as part of the magnetic circuit and as an EMI shield, eliminating the need for separate copper foil shielding layers
Solution Approach 2:
The shielding winding performs multiple functions: it provides magnetic shielding, maintains electrical isolation, and can be integrated with the bobbin structure, reducing overall device complexity
3Object-affected harmful factors
If additional cancellation and balancing windings are installed to reduce displacement current flow, then EMI reduction is achieved, but winding space becomes insufficient and manufacturing cost increases
Solution Approach 1:
The patent applies local quality by positioning the shielding winding specifically between the input and output windings where the parasitic capacitance effect is most significant, rather than adding windings throughout the entire structure
Solution Approach 2:
The patent changes the parameter of winding arrangement by optimizing the position and turns ratio of the shielding winding to achieve EMI reduction with minimal space occupation
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 solution effectively reduces conductivity EMI while preventing damage and cost increases, ensuring compliance with safety standards and efficient power transfer.
Implementation Method 1
the shielding winding is electrically coupled to the input winding and capacitively coupled to the output winding. An electric potential is produced by the capacitive coupling between the shielding winding and the output winding
Implementation Method 2
the auxiliary winding is electrically coupled to the shielding winding and the input winding and further capacitively coupled to the output winding
Implementation Method 3
When a controller U1 controls the switching of a switching device Q1, the input terminal of the power supply 1 transmits the stored energy to an output terminal through a core 103
Data Source
AI summary
An energy transfer apparatus is developed for reducing a conductivity electromagnetic interference and manufacturing method. The energy transfer apparatus comprises a core, an input winding, an output winding, a supply voltage and a supply winding. The supply winding includes a shielding winding and an auxiliary winding. The input winding receives an input voltage for outputting the output voltage through the core and the output winding. The shielding winding and the auxiliary winding generate the supply voltage through the core. By setting of wire size and winding turns of the shielding winding, the conductivity electromagnetic interference is reduced for stabilizing an electric potential between an input-grounding terminal and an output-grounding terminal of the energy transfer apparatus.