LED Thermal Management via Temperature-Adaptive DC/DC Current Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing DC/DC converters with fixed target output current values are inadequate for optimal thermal management of LEDs in motor vehicle lighting, leading to potential LED deterioration at high temperatures and reduced light performance at lower temperatures, especially in automotive applications where constant luminosity is crucial for safety.
Innovation Solution
A DC/DC converter system with a servo loop and adjustment circuit that adjusts the current intensity based on ambient temperature measurements, using a thermistor and current mirror to ensure the current supplied to LEDs does not exceed their maximum acceptable value, thereby maintaining optimal performance and longevity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a minimum constant target current value is used to avoid excessive current at high temperatures, then LED reliability is improved, but light performance is worsened at lower temperatures
Solution Approach 1:
The patent applies dynamics by making the target current value adjustable rather than fixed. The control unit modifies the target current based on temperature measurements, allowing the system to adapt between a minimum constant value (for reliability at high temperatures) and higher values (for optimal light performance at lower temperatures).
Solution Approach 2:
The patent changes the parameter of target current value based on temperature conditions. The control unit receives temperature information and adjusts the target current parameter dynamically, transitioning between different current levels to resolve the contradiction between reliability and light performance across varying temperature conditions.
2Device complexity
If DC/DC converters with fixed target output current are used, then device complexity is reduced, but thermal management capability is worsened
Solution Approach 1:
The patent implements feedback by having the control unit receive temperature information from temperature sensors and use this feedback to adjust the target current value. This closed-loop feedback mechanism enables thermal management without requiring a complete redesign of the DC/DC converter architecture.
Solution Approach 2:
The control unit acts as an intermediary between the temperature sensing system and the DC/DC converter. It receives temperature data and translates it into appropriate target current adjustments, mediating between the fixed converter and the variable thermal conditions without adding significant complexity to the converter itself.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for efficient thermal management of LEDs by adjusting current levels according to temperature, maximizing luminescence at lower temperatures and preventing overheating, thus enhancing LED longevity and maintaining performance consistency across varying temperatures.
Implementation Method 1
an adjustment circuit, adapted to adjust said value into a slaved value as a function of a measurement of the temperature obtained by means of measuring the ambient temperature
Implementation Method 2
a DC/DC converter capable of converting an input electric voltage into an output electric voltage
Data Source
Figure 1~2
AI summary
The invention relates to a device and method for controlling the power supply of light sources, preferably light emitting diodes (LED). The invention is characterised in that it allows the thermal management of LEDs without requiring the use of a programmable DC/DC converter, by systematically adjusting an automatic control value of the DC/DC converter used.