LED Driver Circuit with Segmented Regulators for Power Efficiency
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Solution Overview
Problem
Existing LED driver circuits face inefficiency due to the need for a common switching regulator to supply the highest voltage drop across series connected LEDs, leading to unnecessary power dissipation in strings with lower voltage drops, especially in battery-powered systems where power is a premium.
Innovation Solution
An electronic circuit with current and voltage control mechanisms that adjust the current through each LED string to maintain a predetermined average current, allowing for efficient power delivery by alternating between two currents, thereby minimizing power loss across all strings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a common switching regulator supplies the highest voltage drop across all series connected LED strings, then all LED strings can be driven, but power dissipation increases unnecessarily for strings with lower voltage drops
Solution Approach 1:
The patent divides the common switching regulator into individual switching regulators for each LED string. Each regulator independently controls its associated LED string, allowing voltage and current optimization per string rather than forcing all strings to operate at the highest voltage level. This segmentation eliminates unnecessary power dissipation in strings with lower voltage requirements.
Solution Approach 2:
The patent implements dynamic control where each LED string's switching regulator adjusts its output voltage and current based on the specific forward voltage characteristics of that string. This dynamic adaptation allows each string to operate at its optimal voltage level rather than a fixed high voltage, reducing overall power dissipation while maintaining brightness consistency.
2Reliability
If a fixed voltage switching regulator supplies enough voltage for the highest voltage drop LED string, then all strings can operate, but efficiency decreases for strings with lower voltage drops
Solution Approach 1:
The patent applies local quality by giving each LED string its own switching regulator that is optimized for that specific string's voltage requirements. Instead of a uniform high-voltage output from a single regulator, each regulator tailors its output characteristics to the local needs of its associated LED string, improving overall system efficiency while ensuring reliable operation of all strings.
Solution Approach 2:
The patent changes the operating parameters (voltage and current) of each switching regulator dynamically based on the forward voltage characteristics of its associated LED string. This parameter optimization allows each string to operate at its most efficient point, reducing total power consumption while maintaining consistent brightness across all strings.
Data Source
AI summary
Electronic circuits and methods include provisions for passing a first current through a diode during a first time interval and for passing a second different current through the diode during a second different time interval. The first current is selected to achieve a predetermined voltage at a node of the diode. A duty cycle of the first current relative to the second current is selected to achieve a predetermined average current passing through the diode. In some arrangements, the diode is a light emitting diode.