LED Driver Feedback Arrangement for Adaptive Power Limiting

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Solution Overview

Problem

Existing LED drivers face suboptimal performance due to voltage limit mechanisms failing to account for selected nominal output current levels, leading to inefficient voltage control and potential exceeding of maximum output power.

Innovation Solution

A driver system that generates a common reference potential to adjust both nominal current levels and adaptive maximum output voltage, ensuring their product remains constant, with feedback mechanisms controlling power supply to prevent exceeding predefined maximum power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed voltage limit mechanism is applied to LED drivers with multiple nominal current levels, then voltage control is simplified, but voltage control performance becomes suboptimal because the voltage limit fails to account for the applied nominal level of output current

Engineering Contradiction:
Improvevoltage control mechanismVSAvoidvoltage control performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements dynamic voltage limiting by making the maximum output voltage limit dependent on the selected nominal output current level. When the nominal output current level changes, the maximum output voltage limit automatically adjusts accordingly. This dynamic adaptation ensures optimal voltage control performance for each current level while maintaining a relatively simple control mechanism structure.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the output voltage is limited to ensure compliance with safety standards and maximum output power, then safety and power management are improved, but the voltage control becomes less flexible across different current levels

Engineering Contradiction:
Improvesafety and power managementVSAvoidvoltage control adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the voltage limit parameter dynamically based on the selected nominal output current level. Instead of using a single fixed voltage limit, the system adjusts the maximum output voltage parameter according to the operating conditions. This allows the voltage control to adapt to different current levels while ensuring safety standards and maximum output power compliance are maintained.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If separate voltage control mechanisms are implemented for each nominal current level, then voltage control precision is improved, but device complexity increases

Engineering Contradiction:
Improvevoltage control precisionVSAvoidcontrol mechanism structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a universal voltage control mechanism that serves multiple nominal current levels through a single adaptive system. Rather than implementing separate control mechanisms for each current level, the system uses one versatile controller that automatically adjusts the voltage limit based on the selected current level. This achieves precise voltage control for each level while avoiding the complexity of multiple separate control circuits.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2958400B1A feedback arrangement for a LED driver
Publication Date: 2017.12.27 HELVAR OY AB
  • EP2958400B1 patent drawingFigure 1~2
  • EP2958400B1 patent drawingFigure 3~5
  • EP2958400B1 patent drawingFigure 6~7

AI summary

According to an example embodiment, a driver for operating one more LEDs is provided. The driver comprises an output for connecting the one or more LEDs, power source means for supplying power to said output, reference generation means for generating a common reference potential in dependence of a selectable component connectable to the driver, first feedback means for providing current feedback in dependence of said common reference potential, which current feedback is indicative of a level of an output current supplied to said output in relation to a nominal current level, second feedback means for providing voltage feedback in dependence of said common reference potential, which voltage feedback is indicative of an output voltage across nodes of said output in relation to an adaptive maximum output voltage, and control means for controlling the power source means based at least on said current feedback and said voltage feedback such that the power supplied to said output does not exceed a predefined maximum power.