Interface Current Channeling Circuit for Wide-Range CCT Tuning
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Solution Overview
Problem
Conventional tunable white lighting systems face challenges in achieving a wide range of color temperature tunability using only two LED arrays powered by a two-channel driver, as the color points between the desired CCTs may be far below the black body line, requiring additional complexity and cost with a three-channel driver.
Innovation Solution
An interface currents channeling circuit converts two current channels of a conventional two-channel driver into three driving currents, allowing the same driver to power two or three LED arrays, including a neutral white array, to achieve three-step MAE BBL color temperature tunability over a wide range, reducing circuit complexity and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a two-channel driver is used to power two LED arrays, then the device complexity and cost are reduced, but the color temperature tunability range and precision are limited
Solution Approach 1:
The patent segments the color temperature tuning into three distinct steps using three LED arrays with different correlated color temperatures (CCTs). Each LED array is responsible for a specific portion of the CCT range, allowing precise control over the color temperature transition while maintaining a relatively simple two-channel driver architecture.
Solution Approach 2:
The patent changes the parameter of correlated color temperature by using three LED arrays with different fixed CCTs (e.g., warm white, neutral white, and cool white). By adjusting the drive currents to these arrays, the system achieves precise CCT tuning across a wide range without requiring a complex driver.
2Manufacturing precision
If a three-channel driver is used to achieve wide CCT tunability, then the color temperature tunability range and precision are improved, but the device complexity and cost increase
Solution Approach 1:
The patent makes the two-channel driver universal by enabling it to control three LED arrays through current channeling. The same two-channel driver can power either two LED arrays or three LED arrays, making it a multi-functional component that reduces overall system complexity and cost while maintaining wide CCT tunability.
Solution Approach 2:
The patent introduces current channeling circuitry as an intermediary between the two-channel driver and the three LED arrays. This intermediary converts the two drive currents into three controlled currents, enabling precise control of each LED array without requiring an additional driver channel.
3Device complexity
If only two LED arrays are used, then the device complexity is reduced, but the color points fall far below the black body line
Solution Approach 1:
The patent applies local quality by using three LED arrays with different correlated color temperatures (e.g., warm white, neutral white, and cool white). Each LED array is optimized for a specific portion of the color temperature spectrum, allowing the system to achieve color points that closely follow the black body line across the entire CCT range.
Data Source
AI summary
An interface currents channeling circuit may be used to convert two current channels of a conventional two-channel driver into three driving currents for the three strings of LEDs. By doing so, the same two channel driver can be used for applications requiring just two LED arrays as well as three LED arrays.