Resonant Hybrid Flyback Control for Wide-Range LED Dimming
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Solution Overview
Problem
Current resonant hybrid flyback converters for LED-based loads lack efficiency and reliability, particularly in ensuring a safe operation, minimum resonant current, and a wide output operation window.
Innovation Solution
A resonant hybrid flyback converter system comprising a half-bridge circuit with high-side and low-side switches, a flyback resonant tank, and a processing unit that senses LED current to control the on-time of the switches, allowing for efficient and reliable operation by maintaining a minimum resonant current and wide output operation window.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional resonant hybrid flyback converters are used for LED-based loads, then the basic power conversion function is achieved, but efficiency and reliability are insufficient, particularly in safe operation, minimum resonant current maintenance, and output operation window
Solution Approach 1:
The patent implements a feedback control mechanism where the processing unit senses the LED current and adjusts the on-time of the low-side and high-side switches accordingly. This closed-loop control ensures the resonant tank maintains minimum resonant current while operating efficiently across a wide output window, resolving the contradiction between reliability and energy loss by dynamically optimizing operation parameters based on actual load conditions
Solution Approach 2:
The patent employs dynamic adjustment of switch on-times based on sensed LED current. The processing unit continuously modifies the operating parameters of the half-bridge circuit to maintain optimal resonant conditions, enabling the system to adapt to varying load requirements while preserving both efficiency and reliability across different operating points
2Adaptability or versatility
If the output operation window is widened to support dimming to 1% and wide LED voltage range, then adaptability is improved, but control precision and efficiency may deteriorate
Solution Approach 1:
The feedback control mechanism senses LED current and adjusts switch on-times in real-time, maintaining precise control even at extreme dimming levels down to 1% and across wide LED voltage ranges. This enables the system to widen the output operation window while preserving control accuracy through continuous parameter optimization
Solution Approach 2:
The patent changes operating parameters (switch on-times) dynamically based on the desired output level and actual load conditions. By adjusting the on-time of low-side and high-side switches according to sensed LED current, the system achieves precise control across the entire output window from 1% dimming to full power while maintaining efficiency
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 system ensures high efficiency and reliability, enabling safe operation with a minimum resonant current and a wide output operation window, supporting dimming to 1% and a wide LED voltage range while reducing inefficiencies and maintaining accuracy.
Implementation Method 1
resonant hybrid flyback converter
Implementation Method 2
transformer with a primary side and a secondary side
Data Source
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AI summary
A resonant hybrid flyback converter (10) for a LED-based load (13c) is provided. Said resonant hybrid flyback converter (10) comprises a half-bridge (11) comprising a high-side switch (11a) and a low-side switch (11b), a flyback resonant tank (12) comprising a transformer with a primary side (15a) and a secondary side (15b), and a processing unit (14). In this context, the half-bridge (11) is configured to supply said primary side (15a), wherein the secondary side (15b) is configured to supply the LED-based load (13c). Additionally, the processing unit (14) is configured to sense a LED current with respect to the LED-based load (13c). In further addition to this, the processing unit (14) is configured to control an on-time of the low-side switch (11b) and/or an on-time of the high-side switch (11a) on the basis of the LED current.