LED Lighting Control Apparatus Voltage Converter Current Regulation
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Solution Overview
Problem
Existing LED lighting systems face challenges with constant voltage power supplies, including difficulties in managing current fluctuations and achieving precise control over light intensity and color temperature, especially when dealing with LEDs of varying forward voltages and temperature changes, leading to inefficiencies and visible flicker.
Innovation Solution
A modular LED architecture that employs a voltage converter to regulate output voltage between a high and low voltage rail, using a control module to adjust the voltage converter's output based on current feedback, and incorporates switching elements to pulse-width modulate LED channels, allowing for independent control of each channel's current and intensity, thereby stabilizing light output and minimizing current fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a constant voltage power supply with adjustable output is used to accommodate LEDs with different forward voltages, then the system can adapt to varying LED characteristics, but the power supply becomes more expensive and difficult to source
Solution Approach 1:
A voltage converter is introduced as an intermediary component between the fixed output voltage power supply and the LED channels. The voltage converter dynamically adjusts the voltage to match the forward voltage requirements of different LED channels, enabling the use of simple fixed-voltage power supplies while maintaining adaptability to varying LED characteristics.
2Device complexity
If multiple LED channels are connected in parallel to a single voltage converter, then the device complexity is reduced, but current fluctuations increase and control precision deteriorates
Solution Approach 1:
The LED channels are segmented into groups, with each group assigned to a dedicated voltage converter. This segmentation allows independent control and compensation for current fluctuations within each group, maintaining control precision while reducing the total number of converters compared to having one per channel.
3Ease of operation
If PWM dimming is used to control light intensity, then the ability to vary light output is achieved, but large current fluctuations occur that increase with total current
Solution Approach 1:
A feedback control system is implemented where the actual current through each LED channel is measured and fed back to the voltage converter. The converter dynamically adjusts the output voltage to compensate for current fluctuations caused by PWM dimming, maintaining stable operation even at high total currents.
4Adaptability or versatility
If LEDs with different forward voltages are connected in parallel, then the system can accommodate manufacturing tolerances, but discrepancies cause control problems and affect light output stability
Solution Approach 1:
The voltage converter employs dynamic voltage adjustment to adapt to the varying forward voltage requirements of different LED channels. By continuously monitoring and adjusting the voltage output for each channel, the system maintains stable light output despite manufacturing tolerances and temperature variations in the LEDs.
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 enables precise control over light intensity and color temperature, reduces current fluctuations, and enhances the stability and efficiency of LED lighting systems by using a single voltage converter for multiple LED channels, improving modularity and reducing the strain on power supplies.
Implementation Method 1
a voltage converter operable to receive an input voltage and generate an output voltage defined between a high voltage rail and a low voltage rail
Implementation Method 2
incorporates switching elements to pulse-width modulate LED channels, allowing for independent control of each channel's current and intensity
Implementation Method 3
at least two LED channels coupled in parallel are operable to be coupled between the high voltage rail and the low voltage rail
Data Source
AI summary
A lighting apparatus that may comprise a voltage converter operable to supply a current to at least two LED channels coupled between a high voltage rail and a low voltage rail coupled to the voltage converter output is disclosed. The LED channels may be operated to selectively allow a current to flow through them. The lighting apparatus may also have a control module operable to control the total current from the voltage converter and the current through each of the LED channels. The control module may also be operable to set the respective control signals to maintain a constant total current from the voltage converter while permitting aspects of the light output including, the intensity, color, and color temperature to be set and varied. Additionally, the control module may be operable to synchronize the various control signals, obtain a representative sample of the current through the voltage converter, and operate in different modes.