Lighting Device Constant-Current Control for Color Temperature Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lighting devices with multiple light emitting diodes (LEDs) face challenges in maintaining consistent current flow due to individual differences in constant current circuits, leading to variations in light intensity, which complicates the configuration and accuracy of color temperature control.
Innovation Solution
A lighting device with a simplified configuration that includes a first and second switching element connected in series to each light source, a controller to output driving signals for PWM control, and a constant-current controller to detect and maintain constant current flow through both sources, ensuring accurate color temperature adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If independent constant current circuits are used to control each light emitting diode, then current control is achieved, but current variation occurs due to individual differences in the constant current circuits
Solution Approach 1:
The patent combines multiple light sources with different color temperatures into a single integrated lighting device with a unified constant current control circuit. This merging approach ensures that all light sources receive consistent current control while allowing individual intensity adjustment through PWM signals, thereby eliminating current variation caused by separate constant current circuits and achieving both reliable control and manufacturing precision.
2Reliability
If light source intensities are detected and controlled based on emitted light intensities to eliminate current variation, then current consistency is improved, but device complexity increases
Solution Approach 1:
The patent extracts the intensity detection and control function from the main constant current control circuit by using a separate PWM control circuit. This allows the constant current control to remain simple and reliable while the PWM circuit handles the sophisticated intensity adjustment based on detected light intensities, thereby maintaining current consistency without significantly increasing overall device complexity.
3Adaptability or versatility
If multiple light sources with different color temperatures are used, then color temperature adjustment capability is improved, but current control accuracy deteriorates due to individual differences
Solution Approach 1:
The patent applies local quality control by allowing each light source to have its own intensity adjustment capability through individual PWM control signals while maintaining统一的 constant current control. This enables different color temperature light sources to operate at optimized current levels tailored to their specific characteristics, thereby achieving both color temperature versatility and current supply accuracy for each light source.
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
The solution allows for consistent current supply to LEDs with different color temperatures, simplifying the circuitry and improving the accuracy of color temperature control while reducing flicker and intensity ripples, resulting in a stable and adjustable lighting output.
Implementation Method 1
a plurality of light emitting diodes which emit light having different colors
Implementation Method 2
a first switching element connected in series to the first light source, and a second switching element connected in series to the second light source
Data Source
AI summary
A lighting device which causes a first light source to emit illumination light and a second light source to emit illumination light having a color temperature higher than a color temperature of the illumination light emitted by the first light source includes: an illuminator which includes a first switching element connected in series to the first light source, and a second switching element connected in series to the second light source; an illumination controller which controls the illuminator to place at least one of the first switching element and the second switching element into an off state; and a constant-current controller which detects a sum of values of currents flowing through the first light source and the second light source, and controls the first switching element and the second switching element based on the sum.