Anti-Parallel LED String Control With a Single Driver
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing luminaire systems face challenges with increased space and cost due to multiple drivers, uneven voltage distribution in anti-parallel LED configurations, and complexity in controlling light elements.
Innovation Solution
A light system with anti-parallel LEDs connected in series, using a single driver and simple control circuitry to selectively activate first and second groups of LEDs in different modes, reducing connection lines and ensuring robust control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If separate drivers are used for driving different groups of LEDs, then independent control of LED groups is achieved, but space and cost for drivers increase
Solution Approach 1:
The patent merges multiple driver functions into a single driver by using anti-parallel LED connections. The single driver alternates current direction to activate different LED strings, eliminating the need for multiple separate drivers while maintaining independent control capability.
Solution Approach 2:
The system uses periodic alternation of current direction through the anti-parallel LED connections. The single driver switches current flow between positive and negative directions in alternating cycles, enabling different LED groups to be activated at different time periods.
2Device complexity
If a single driver is used with switching elements to control different branches, then driver count is reduced, but the driver must cope with power changes and handle the sum of power needed in each branch
Solution Approach 1:
The driver operates in periodic cycles, activating only one LED string at a time by alternating current direction. This temporal separation means the driver only needs to handle the power requirement of a single string at any given moment, not the sum of all strings.
Solution Approach 2:
The anti-parallel connection configuration creates locally optimized current paths where current flows through only one string per half-cycle. This local activation pattern reduces the instantaneous power burden on the driver compared to simultaneous activation of all strings.
3Device complexity
If first and second LED strings are connected in anti-parallel with current sent alternatively, then single driver is used, but there is risk of over-tension over non-activated LEDs due to uneven voltage distribution
Solution Approach 1:
The patent introduces switching elements as intermediaries between the driver and anti-parallel LED strings. These switches actively control current routing, ensuring that when one string is active, the other is properly isolated, preventing uneven voltage distribution and over-tension risks.
Solution Approach 2:
The system dynamically changes the electrical state parameters (conductivity, resistance) of the LED strings through controlled switching. By adjusting the switching timing and state, the system optimizes voltage distribution across anti-parallel connections, preventing over-tension on non-activated 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
The system achieves compact design, efficient power management, and precise control of light output, including shape, position, color, and intensity, while minimizing driver load fluctuations.
Implementation Method 1
a first LED (1) and a second LED (2) connected in anti-parallel... the DC current is used to activate the first LED(s) (1)... and/or the second LED(s) (2)
Implementation Method 2
a first LED (1) and a second LED (2) connected in anti-parallel
Data Source
Figure 1A~2
Figure 3A
Figure 3B
AI summary
Light system, comprising a driver to generate a DC current, at least one first group, a first group thereof comprising a first and a second LED connected in anti-parallel, at least one second group, a second group thereof comprising a first and a second LED connected in anti-parallel; said at least one second group being connected in series with said at least one first group, and control circuitry for selectively operating in at least one first mode and at least one second mode, wherein in the at least one first mode, the DC current is used to activate the first LED(s) of the at least one first group and/or the at least one second group; and in the at least one second mode, the DC current is used to activate the second LED(s) of the at least one first group and/or the at least one second group.