Adaptive LED Driver Control via Processing Device
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Solution Overview
Problem
The unpredictable voltage drop across different LED strings due to manufacturing variations makes it difficult to operate them in a power-efficient manner while maintaining precise control over brightness, and conventional solutions are often inefficient or costly.
Innovation Solution
A system comprising a separate processing device and LED driver, where the processing device determines duty cycles for the LED strings based on programmed current levels and baseline settings, allowing for precise control over brightness and efficient current regulation without the need for complex circuitry in the LED driver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional current regulation techniques are used for LED strings with different voltage drops, then precise control over brightness can be maintained, but power efficiency deteriorates due to energy dissipation in driving circuitry
Solution Approach 1:
The patent changes the operating parameters of LED strings by allowing different peak current levels for different strings based on their individual forward voltage characteristics. The system determines optimal current levels that equalize brightness across strings while minimizing power dissipation, rather than forcing all strings to operate at the same current level.
2Measurement precision
If additional circuitry is added to compensate for LED manufacturing variations, then precise brightness control can be achieved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the complex compensation logic from the hardware circuitry and relocates it to software/firmware running on a processor. The system uses algorithms to calculate appropriate duty cycles and current levels for each LED string based on measured brightness feedback, eliminating the need for complex analog compensation circuits.
Solution Approach 2:
The patent replaces mechanical/electrical compensation circuits with a digital control system. Instead of using additional analog components to compensate for LED variations, the system uses digital processing to measure brightness and calculate appropriate driving parameters, substituting physical circuit complexity with computational logic.
3Measurement precision
If duty cycle calculations are performed in the LED driver itself, then precise control can be achieved, but the LED driver requires complex circuitry increasing component cost
Solution Approach 1:
The patent segments the control functions between two separate components: the LED driver hardware that handles current regulation and switching, and a processor that performs duty cycle calculations and brightness compensation algorithms. This division allows the LED driver to remain simple while the processor handles the complex computational tasks.
Data Source
AI summary
A system that provides an intelligent approach to driving multiple strings of LEDs. A processing device determines an optimal current level for each LED string from a limited set of allowed currents. The processing device also determines a PWM duty cycle for driving the LEDs in each LED string to provide precise brightness control over the LED string. The settings for the current level and duty cycle are transmitted to an LED driver for regulating the current and on-off times of the LED strings. Beneficially, the system reduces the size of the LED driver while leveraging existing resources available in the processing device to operate the LEDs in a power efficient manner.