LED Driver Control Method Preventing Flicker via Variable Reference Voltage
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Solution Overview
Problem
Conventional LED driving circuits face issues with flicker effects due to current variations during dimming, as they rely on fixed reference voltages, leading to inefficient power conversion and potential inability to maintain constant current supply.
Innovation Solution
A control method and device that detect current variations in real-time, adjust a variable reference voltage, and generate a voltage control signal to dynamically adjust the output voltage, ensuring appropriate headroom voltages and preventing flicker effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed reference voltage is used in conventional LED driving circuits, then the circuit structure is simple, but flicker effects occur during dimming due to current variations
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed reference voltage to a variable reference voltage that dynamically adjusts based on detected current variations. The control circuit monitors LED current in real-time and modifies the reference voltage accordingly, enabling the system to adapt to changing operating conditions during dimming and prevent flicker effects while maintaining stability.
Solution Approach 2:
The patent implements feedback by incorporating a current detection mechanism that continuously monitors LED current and feeds this information back to the control circuit. This feedback loop enables the control circuit to adjust the reference voltage in response to actual current variations, ensuring stable operation and preventing flicker during dimming without requiring complex additional hardware.
2Loss of energy
If the output voltage is adjusted slowly to maintain stability, then the system is stable, but power conversion efficiency decreases due to prolonged adjustment time
Solution Approach 1:
The patent applies dynamics by enabling the output voltage to adjust dynamically in response to current variations. Instead of slow, incremental adjustments, the system can quickly modify the reference voltage based on real-time current detection, allowing the output voltage to reach appropriate levels faster and improving power conversion efficiency while maintaining stability through controlled, intelligent adjustment.
3Reliability
If the headroom voltage is increased to prevent flicker, then flicker effect is reduced, but power consumption increases and conversion efficiency decreases
Solution Approach 1:
The patent applies dynamics by making the reference voltage adaptive rather than fixed or constantly increased. The system detects current variations and adjusts the reference voltage only when necessary, preventing flicker without requiring continuous headroom voltage increase. This dynamic adjustment ensures flicker prevention while minimizing power consumption and maintaining high conversion efficiency.
Data Source
AI summary
A control method capable of preventing flicker effect for a light source module includes detecting variation situations of a driving current passing through the light source module to generate a current detection signal, adjusting a variable reference voltage according to the current detection signal, obtaining a feedback voltage from the light source module, generating a voltage control signal according to the feedback voltage and the variable reference voltage, and generating an output voltage according to the voltage control signal to drive the light source module.