Quasi-Planar Transformer Insulation for Low-Profile Power Supplies
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Solution Overview
Problem
Conventional isolated switchmode power supplies face challenges in achieving high power density, reduced height, and minimized leakage inductance, particularly due to the limitations of wire-wound-on-a-bobbin transformers, which often require additional insulation materials and assembly processes that increase costs and complexity.
Innovation Solution
The use of a quasi-planar transformer design with primary and secondary windings covered by an electrical insulator only on their upper portions, which are magnetically coupled by a core, allows for a compact and efficient power supply configuration that reduces the need for additional insulation materials and assembly processes, such as tape and protective films, while maintaining proper spacing and preventing damage during assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wire-wound-on-a-bobbin transformers are used, then insulation is provided, but additional insulation materials and assembly processes are required which increase costs and complexity
Solution Approach 1:
The patent combines the insulation function with the electrical insulator that is already part of the quasi-planar transformer structure. The insulator serves dual purposes: providing electrical insulation between windings and eliminating the need for separate insulation materials like tape and protective films, thereby reducing assembly complexity while maintaining insulation reliability
Solution Approach 2:
The electrical insulator in the quasi-planar transformer is designed to perform multiple functions simultaneously: it provides electrical insulation, structural support, and protection during assembly. This multi-functional design eliminates the need for separate insulation components and their associated assembly processes, directly addressing the contradiction between reliable insulation and assembly complexity
2Reliability
If conventional wire-wound transformers are used, then windings are protected, but height and power density are compromised
Solution Approach 1:
The patent transitions from a conventional three-dimensional wire-wound structure to a quasi-planar configuration where windings are arranged in a more two-dimensional layout. This dimensional change allows the windings to be covered by the electrical insulator on upper portions only, providing protection while significantly reducing the height of the transformer and improving power density
3Reliability
If full encapsulation with insulation materials is applied, then complete protection is achieved, but heat dissipation is reduced
Solution Approach 1:
The patent applies electrical insulation locally only to the upper portions of the windings rather than full encapsulation. This localized insulation approach provides necessary protection where electrical isolation is most critical while leaving the lower portions exposed for effective heat dissipation, thus resolving the contradiction between protection and heat dissipation
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 design enhances power density, reduces leakage inductance, and lowers production costs by eliminating the need for tape and protective films, while ensuring secure assembly and improved heat transfer through partial encapsulation, facilitating automated production and integration into circuit boards.
Implementation Method 1
a core magnetically coupling the one or more primary windings and the one or more secondary windings
Data Source
AI summary
An isolated switch-mode power supply includes at least one input, at least one output, and a power circuit coupled between the at least one input and the at least one output for converting an input voltage or current to an output voltage or current. The power circuit includes a transformer having one or more primary windings, one or more secondary windings, an electrical insulator, and a core magnetically coupling the one or more primary windings and the one or more secondary windings. Upper portions of the primary and secondary windings are covered with the electrical insulator. Other example switchmode power supplies, transformers, magnetic chokes and methods are also disclosed.