LED Control Circuit with Dynamic Feedback Switching for Flicker Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In display panels, low-level PWM signals converted to current signals result in low current values, leading to large voltage amplitude fluctuations at the feedback end of LEDs, causing continuous flickering of the light-emitting diode.
Innovation Solution
A control circuit comprising a sampling sub-circuit to collect level signals from PWM signals and a switching sub-circuit that connects to signal feedback ends with multiple feedback points, allowing the switching sub-circuit to switch between modes based on the level signal and a preset threshold, controlling mutual independence or association of feedback points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If low-level PWM signals are converted to current signals, then the brightness control function is achieved, but the current value becomes low causing large voltage fluctuation and continuous flickering
Solution Approach 1:
The patent merges multiple feedback points into parallel groups that share common circulating lines. When the PWM duty cycle is low, feedback points are associated together to form parallel groups, allowing current to be summed across multiple paths. This increases the total current magnitude and reduces voltage fluctuations, thereby reducing flickering while maintaining brightness control functionality.
2Adaptability or versatility
If feedback points are provided with mutually independent circulating lines, then each feedback point can be controlled independently, but the current magnitude remains low causing large voltage fluctuation
Solution Approach 1:
The patent implements dynamic reconfiguration of feedback point connections based on the PWM duty cycle. When duty cycle is high, feedback points operate independently for precise control. When duty cycle is low, feedback points are dynamically associated into parallel groups sharing common circulating lines. This dynamic switching optimizes both control flexibility and voltage stability across different operating conditions.
Data Source
AI summary
A control circuit includes a sampling sub-circuit, a switching sub-circuit, and a working power supply, where the sampling sub-circuit is configured to collect a level signal corresponding to a pulse width modulation signal, one end of the switching sub-circuit is connected to the sampling sub-circuit, the other end is connected to at least one group of signal feedback ends, each of which includes at least two feedback points, the feedback points are configured to be connected to a light emitting element, and the switching sub-circuit is capable of being switched between a first mode and a second mode based on a relationship between the level signal and a preset threshold.