Single Current Regulator for LED String Equalization
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Solution Overview
Problem
High power LED lighting applications face challenges in driving multiple LEDs with equal current, leading to excessively high voltages and inefficiencies due to the need for multiple current regulators, which increase costs and reduce system efficiency.
Innovation Solution
A system comprising a single multiple output current regulated converter that arranges current regulated outputs and LED strings in a single current loop configuration, providing a substantially constant and equal current to each LED string, thereby reducing voltage and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple separate current regulators are used for each LED string, then current regulation is achieved, but system cost increases and efficiency decreases
Solution Approach 1:
The patent combines multiple separate current regulators into a single current regulator that controls multiple LED strings through a series-parallel switching network. This single regulator uses a microcontroller to generate PWM signals that control MOSFET switches, allowing one regulator to perform the function of what would traditionally require multiple separate regulators, thereby reducing component count, cost, and complexity while maintaining current regulation capability.
2Reliability
If LEDs are connected in series to ensure equal current, then current equality is achieved, but voltage becomes excessively high
Solution Approach 1:
The patent segments the LED strings into groups that can be connected in series or parallel based on control signals. The switching network divides LED strings into different configurations, allowing the system to maintain equal current while distributing voltage across multiple parallel branches rather than requiring all LEDs to be in a single high-voltage series chain. This segmentation enables voltage reduction while preserving current equality through coordinated switching.
Solution Approach 2:
The patent implements dynamic switching between series and parallel configurations of LED strings using MOSFETs controlled by PWM signals from a microcontroller. This dynamic reconfiguration allows the system to adapt the voltage and current distribution in real-time, maintaining equal current across LED strings while adjusting voltage levels to remain within safe operating limits, rather than being fixed in a single high-voltage series configuration.
3Ease of operation
If separate current loops are used for each LED string, then individual regulation is achieved, but current balance between strings deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where a single current regulator monitors the total current and uses PWM-controlled MOSFET switches to distribute current evenly across multiple LED strings. The microcontroller adjusts the duty cycle of each PWM signal based on feedback from current sensing, ensuring that each LED string receives equal current despite variations in individual string characteristics. This centralized feedback approach maintains better current balance than independent loops where each regulator operates without coordination.
Data Source
AI summary
Systems and methods are provided for providing a substantially constant and equal current to a plurality of current driven loads. In one embodiment, a system is provided that comprises a plurality of current regulated outputs and a plurality of current driven loads. The plurality of current regulated outputs and the plurality of current driven loads are arranged in a single current loop configuration with a respective current regulated output providing an output voltage to a respective current driven load of the plurality of current driven loads.