Single Transformer Resonant Converter for Multiple Outputs
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Solution Overview
Problem
Existing multiple output resonant power supplies require multiple transformers, leading to increased cost and complexity, and suffer from high line frequency ripple components due to varying reflected leakage inductance across different output voltages.
Innovation Solution
A DC to DC resonant converter using trailing edge modulation and amplitude modulation with synchronous rectification, allowing a single power transformer to provide multiple output voltages by controlling the resistance of synchronous field effect transistors and eliminating the need for separate regulating circuits and diodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple power transformers are used to deliver multiple output voltages, then the necessary voltages can be delivered to downstream loads, but the cost and device complexity increase significantly
Solution Approach 1:
The patent applies universality by designing a single power transformer that can deliver multiple output voltages (5V, 3.3V, 12V) simultaneously through multiple secondary windings with different turn ratios. This multi-functional transformer replaces what would traditionally require multiple separate transformers, reducing device complexity while maintaining the ability to provide multiple voltage outputs.
Solution Approach 2:
The patent segments the secondary side of the single transformer into multiple independent winding sets, each configured with specific turn ratios to generate different output voltages. By segmenting the transformer windings and associating each with dedicated synchronous rectifier circuits, the system achieves multiple voltage outputs from a single transformer core.
2Adaptability or versatility
If multiple power transformers are used, then multiple output voltages can be provided, but the density of the power supply decreases
Solution Approach 1:
The patent merges multiple transformer functions into a single integrated power transformer with multiple secondary windings. By combining what would traditionally be separate transformer units into one device, the overall volume is reduced while maintaining the capability to provide multiple voltage outputs, thereby improving power supply density.
3Adaptability or versatility
If prior art resonant converter techniques are used with varying leakage inductance, then different output voltages can be achieved, but high line frequency ripple components appear in the DC outputs
Solution Approach 1:
The patent employs feedback control through synchronous rectifier circuits that use control signals derived from the resonant frequency to regulate the rectification process. This feedback mechanism allows the system to compensate for variations in reflected leakage inductance and maintain stable output voltages with reduced ripple components.
Solution Approach 2:
The patent implements dynamic control by adjusting the timing and duration of control signals to the synchronous rectifiers based on the resonant frequency and load conditions. This dynamic adjustment allows the system to adapt to varying leakage inductance and maintain optimal rectification, reducing output ripple while providing multiple voltage levels.
4Adaptability or versatility
If conventional power supplies are used, then multiple output voltages can be provided, but significant losses occur due to high line frequency ripple
Solution Approach 1:
The patent utilizes periodic resonant oscillations at a specific resonant frequency to transfer energy efficiently from the primary to secondary windings. By operating at resonance, the system minimizes energy losses associated with non-resonant operation and reduces line frequency ripple, thereby improving overall efficiency while maintaining multiple voltage outputs.
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 achieves efficient multiple output voltage regulation with reduced losses and line frequency ripple, maintaining high efficiency and cost-effectiveness by synchronizing the resonant circuit with varying leakage inductance and eliminating the need for additional transformers and diodes.
Implementation Method 1
Multiple voltage DC to DC resonant converter with a single power transformer
Implementation Method 2
resonant synchronous rectification using this single power transformer
Data Source
AI summary
A resonant DC to DC converter circuit receiving an input voltage and capable of delivering multiple output voltages, while maintaining excellent cross-regulation with only one power transformer. The circuit of the invention uses trailing edge modulation, along with a new amplitude modulation arrangement which allows for the use of resonance with synchronous rectification and only a single power transformer. Thus, the circuit provides for DC to DC conversion, as well as an amplitude modulation arrangement.