COB Lighting CCT Compensation Using Temperature Feedback and Auxiliary Light
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Solution Overview
Problem
COB lights experience significant CCT and lumen drift due to temperature variations, leading to inconsistent lighting performance, particularly in applications requiring precise color rendering and stable light output.
Innovation Solution
A lighting system with an integrated light source, power supply, and wireless module in a compact housing, featuring a temperature sensor and channel controller that adjusts the driving current and compensates for CCT and lumen drift by mixing auxiliary light with the COB light output, using look-up tables to determine compensation signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If COB lights operate at high power density to achieve high brightness, then illumination intensity is improved, but CCT drift and lumen depreciation worsen due to temperature rise
Solution Approach 1:
The system incorporates a temperature sensor that continuously monitors the COB temperature and feeds this information back to the control circuit. The control circuit dynamically adjusts the driving current based on the temperature feedback to compensate for CCT drift and maintain consistent color temperature despite high power operation
Solution Approach 2:
The system changes the electrical parameters (driving current, pulse width modulation duty cycle) based on temperature conditions to maintain optimal optical performance. By adjusting these parameters in response to temperature changes, the system compensates for CCT drift and lumen depreciation
2Illumination intensity
If COB lights operate at high power density to achieve high brightness, then illumination intensity is improved, but lumen output stability worsens due to lumen depreciation
Solution Approach 1:
The control circuit uses temperature feedback to dynamically adjust the driving current, compensating for lumen depreciation caused by thermal effects. This feedback mechanism maintains stable lumen output despite high power operation and temperature rise
Solution Approach 2:
The system proactively adjusts the driving current before significant lumen degradation occurs by monitoring temperature trends and preemptively modifying operational parameters to prevent excessive heat accumulation and its associated lumen loss
3Reliability
If temperature monitoring and compensation mechanisms are added to compensate for CCT drift, then CCT consistency is improved, but device complexity worsens
Solution Approach 1:
The temperature sensor, control circuit, and light driver are integrated into a unified system where the control circuit performs both temperature compensation and dimming functions. This merging reduces the need for separate compensation hardware and simplifies the overall device structure
Solution Approach 2:
The control circuit is designed to perform multiple functions: it manages dimming operations, monitors temperature, calculates compensation values, and adjusts driving current accordingly. This multi-functionality eliminates the need for dedicated compensation hardware, reducing device complexity
4Reliability
If temperature monitoring and compensation mechanisms are added to compensate for CCT drift, then CCT consistency is improved, but manufacturing complexity worsens
Solution Approach 1:
The control circuit is designed to integrate temperature compensation functionality into the existing light driver architecture, allowing components to be mounted on standard PCB layouts without requiring specialized assembly procedures or additional manufacturing steps
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
Maintains consistent color temperature and light intensity by dynamically adjusting the light output to compensate for temperature and age-related changes, ensuring accurate and reliable lighting performance.
Implementation Method 1
an auxiliary light configured to generate compensation light for compensating a correlated color temperature (CCT) drift
Data Source
AI summary
A lighting system includes a power supply circuit configured to generate a drive signal for powering a light source based on an input power signal; a temperature sensor configured to measure a light source temperature corresponding to the light source; a current control circuit coupled to the light source and configured to adjust a current of the light source based on the drive signal and a reference signal; a channel controller configured generate the reference signal based on a dimmer setting, and to generate a compensation drive signal based on the light source temperature; and an auxiliary light configured to generate compensation light for compensating a correlated color temperature (CCT) drift in an output light of the light source based on the compensation drive signal.