Series-Connected LED Control with Diverted Current Paths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The widespread adoption of low-voltage LEDs and LED-based lighting units is hindered by the need for energy conversion from higher power supply voltages, which results in conversion inefficiency and the integration challenges posed by power management components like inductors and capacitors.
Innovation Solution
Connecting multiple LEDs in series allows for the use of higher operating voltages, enabling operation directly from line voltage without a transformer, and incorporating controllable current paths and a controller to manage the series current and divert it around individual LEDs as needed, ensuring efficient power delivery across varying voltage conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If multiple LEDs are connected in series to operate directly from line voltage, then the operating voltage is increased and transformerless operation is enabled, but the complexity of current control increases
Solution Approach 1:
The patent divides the series string of LEDs into multiple parallel current paths, with each path containing a subset of LEDs. This segmentation allows independent control of each parallel path, enabling complex lighting effects while maintaining compatibility with series connection for high voltage operation. The controller can selectively activate different parallel paths to achieve desired lighting patterns.
Solution Approach 2:
The patent implements dynamic control by allowing the controller to adjust which parallel current paths are active based on desired lighting effects. The system can dynamically switch between different configurations of parallel paths, enabling flexible control over which LEDs are illuminated and at what intensity, thereby managing the complexity of current control adaptively.
2Adaptability or versatility
If controllable current paths are added to divert current around individual LEDs, then the control flexibility is improved, but the device complexity increases
Solution Approach 1:
The patent merges the control functionality into a single controller that manages multiple parallel current paths. By consolidating the control logic in one device, the patent reduces the need for separate control circuits for each LED or parallel path, thereby achieving high control flexibility without proportionally increasing overall circuit complexity.
Solution Approach 2:
The controller is designed to perform multiple functions: it controls which parallel current paths are active, adjusts the intensity of each path, and can create various lighting effects by coordinating the activation of different LED subsets. This multi-functionality achieves high adaptability and control flexibility without requiring separate specialized circuits for each function.
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 approach increases the overall operating voltage of LED systems, reduces the required voltage for operation, and enhances integration by minimizing the footprint of power management components, thereby improving efficiency and compatibility with conventional power sources.
Implementation Method 1
incorporating controllable current paths and a controller to manage the series current and divert it around individual LEDs as needed
Data Source
AI summary
Methods and apparatus for controlling series-connected LEDs. Two or more LEDs are connected in series between a first node and a second node, wherein a series current flows between the nodes when an operating voltage is applied across the nodes. One or more controllable current paths are connected in parallel with at least a first LED for at least partially diverting the series current around at least the first LED. A controller monitors at least one parameter representative of the operating voltage, determines a maximum number of the series-connected LEDs that can be energized by the operating voltage, and controls the controllable current path(s) so as to increase an amount of the series current that is diverted around at least the first LED when the maximum number is less than a total number of all of the LEDs connected in series. In one example, the foregoing may be implemented as an integrated circuit package to provide a lighting apparatus suitable for automotive applications.