LED Dimming Driver Circuit Using Self-Excited RCC Topology

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional LED dimming driver circuits for TRIAC dimmers have complex structures and low conversion efficiency, leading to issues such as poor dimming linearity, narrow dimming range, and flickering when used with LED lamps.

Innovation Solution

The proposed LED dimming driver circuit employs a self-excited topology-driven RCC (Rectifier Circuit) that includes a rectifier circuit, filter circuit, and power conversion circuit, along with passive bleeder circuits and a power supply loop with a transformer, to regulate and convert the input voltage from a TRIAC dimmer into a stable driving current for LED loads, simplifying the circuit structure and improving efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional peripheral circuit suitable for TRIAC dimmer is used, then compatibility with TRIAC dimmer is achieved, but the circuit structure becomes complex and conversion efficiency decreases

Engineering Contradiction:
Improvecompatibility with TRIAC dimmerVSAvoidcircuit structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs a self-excited topology-driven RCC circuit that uses the input voltage waveform itself to trigger the switching action, eliminating the need for separate triggering circuits. The circuit automatically detects zero-crossing points of the input AC waveform and generates appropriate switching signals, thereby simplifying the overall circuit structure while maintaining TRIAC dimmer compatibility

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts and utilizes only the essential zero-crossing information from the input AC waveform to generate switching signals, rather than requiring complex detection and control circuits. By taking out just the zero-crossing points and using them to trigger the switching action, the circuit achieves simplified structure while maintaining full compatibility with TRIAC dimmer control

Inventive Principle:
Principle #2Taking out (Extraction)

2Adaptability or versatility

If a conventional peripheral circuit suitable for TRIAC dimmer is used, then compatibility with TRIAC dimmer is achieved, but conversion efficiency becomes low

Engineering Contradiction:
Improvecompatibility with TRIAC dimmerVSAvoidconversion efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent utilizes the periodic zero-crossing characteristics of the AC input waveform to synchronize the switching action with the input waveform. By triggering switching events at each zero-crossing point, the circuit achieves efficient power conversion that is naturally synchronized with the AC cycle, minimizing energy loss while maintaining compatibility with TRIAC dimmer control

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent ensures continuous and efficient power conversion by maintaining switching action throughout the AC cycle. The self-excited topology maintains continuous operation of the power conversion circuit, ensuring that energy is continuously and efficiently transferred to the LED load without interruption or significant energy loss, while remaining compatible with TRIAC dimmer control

Inventive Principle:
Principle #20Continuity of useful action

3Adaptability or versatility

If conventional LED dimming driver circuits are used, then TRIAC dimmer compatibility is provided, but dimming performance deteriorates with poor linearity, narrow range and flickering

Engineering Contradiction:
ImproveTRIAC dimmer compatibilityVSAvoiddimming performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent incorporates feedback mechanisms that continuously monitor the output current and adjust the switching duty cycle to maintain linear dimming characteristics. The feedback loop ensures that the LED current remains proportional to the dimming control signal across the entire dimming range, eliminating flickering and achieving uniform dimming performance while maintaining TRIAC dimmer compatibility

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts the switching characteristics based on the input voltage level and dimming control signal. The circuit automatically adapts its operation to different input conditions, maintaining optimal dimming performance across the full range of control signals. This dynamic adjustment capability ensures linear dimming response and prevents flickering while remaining compatible with TRIAC dimmer control

Inventive Principle:
Principle #15Dynamics

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 RCC provides a simple, cost-effective solution with high conversion efficiency, enabling nearly linear conversion of input voltage changes to output current changes, expanding the dimming range and preventing flickering by maintaining stable current delivery to the LED load.

Implementation Method 1

a rectifier circuit configured to rectify the alternating voltage from the TRIAC dimmer into a direct voltage

Methodology Applied
Scientific EffectRectification:

Implementation Method 2

a filter circuit configured to filter the direct voltage

Methodology Applied
Scientific EffectFiltering: Filter (electronic)

Implementation Method 3

a power conversion circuit configured to perform power conversion on the filtered direct voltage, to filter out an alternating voltage component from the filtered direct voltage

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3346803B1Light-emitting diode dimming drive circuit
Publication Date: 2022.10.05 BOE TECHNOLOGY GROUP CO LTD
  • EP3346803B1 patent drawingFigure 1~3B
  • EP3346803B1 patent drawingFigure 4A~5
  • EP3346803B1 patent drawingFigure 6~7

AI summary

The present disclosure provides an LED dimming driver circuit, which includes: a TRIAC dimmer configured to adjust an inputted alternating voltage; and a RCC connected to the TRIAC dimmer and configured to adjust the alternating voltage from the TRIAC dimmer to provide a driving current for an LED load.