LED Load Control Device Color Temperature Convergence
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Solution Overview
Problem
Existing load control systems for LED light sources struggle to smoothly dim the light while maintaining consistent color temperature at low intensity levels, leading to perceptible changes in color that can be visually distracting.
Innovation Solution
A load control device with a control circuit that adjusts the intensity and color temperature of LED light sources by using multiple emitter circuits and drive circuits, and employs limit curves to converge the target color temperature towards specific color temperatures as the intensity level decreases, ensuring smooth dimming and minimal color variation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the intensity level of LED light source is reduced for dimming, then the power consumption is reduced, but the color temperature changes perceptibly becoming visually distracting
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the target color temperature based on the intensity level according to limit curves. As the intensity level decreases, the control circuit modifies the color temperature parameter to converge toward specific color temperatures, preventing perceptible color changes while maintaining smooth dimming operation.
Solution Approach 2:
The system implements dynamics by making the color temperature adaptive rather than fixed. The control circuit continuously adjusts the target color temperature based on the current intensity level and limit curves, allowing the color temperature to change dynamically in a controlled manner that prevents visual distraction during dimming.
2Adaptability or versatility
If multiple emitter circuits with different color temperatures are used to control color temperature, then the color temperature adjustment range is improved, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the light source into multiple emitter circuits, each emitting at a specific color temperature. This allows independent control of each emitter circuit through separate drive circuits, enabling precise color temperature adjustment by selectively activating different segments based on the desired output.
Solution Approach 2:
The system achieves multi-functionality by using the same emitter circuits for both color temperature adjustment and intensity control. The limit curves enable the system to perform multiple functions (color temperature convergence, intensity dimming, and visual quality maintenance) using the existing hardware components without requiring additional specialized elements.
Data Source
AI summary
A load control device for controlling a light source may be configured to control a target color temperature near a low-end intensity level to converge the color temperature towards one or more color temperatures. The light source may include first and second emitter circuits that emit light having first and second color temperatures, respectively. The load control device may control the first and second emitter circuits to cause a present color temperature of the cumulative light emitted by the light source to be controlled towards the target color temperature. When a target intensity level is less than a threshold intensity level, the control circuit may limit the target color temperature according to at least one limit curve that causes the target color temperature to converge towards at least one of the first or second color temperatures as the target intensity level decreases towards the low-end intensity level.