AC LED Module Waveform Modulation for Power Factor
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Solution Overview
Problem
Conventional AC light emitting devices have low power factor and high flicker extent due to high threshold voltage requirements, leading to inefficient light emission and increased power wastage when using AC voltage sources.
Innovation Solution
The AC light emitting device modulates the waveform or frequency of the AC voltage source and adjusts the connection states of LEDs to ensure uniform current flow, allowing for efficient light emission by turning on LEDs with different micro diode areas according to the voltage source, thereby improving power factor and reducing flicker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple micro-diodes are connected in series to form a string with high threshold voltage (90V or higher), then the device can be powered by mains voltage, but the power factor becomes too small (less than 0.8) and real power is wasted
Solution Approach 1:
The patent divides the single high-threshold-voltage string into multiple parallel strings with lower threshold voltages. Each string contains fewer micro-diodes in series, reducing the threshold voltage requirement. This segmentation allows the AC LED module to conduct current for a larger portion of the AC cycle, improving the power factor and reducing energy wastage while still being compatible with mains voltage operation.
Solution Approach 2:
The patent dynamically adjusts the connection configuration of micro-diodes between series and parallel arrangements based on operating conditions. By controlling the switching elements, the system can transition between different connection states to optimize the power factor under varying voltage and current conditions, preventing excessive power wastage while maintaining compatibility with mains voltage.
2Ease of operation
If the threshold voltage is set high (90V or higher) to enable mains operation, then the device can work with AC voltage source, but the proportion of micro-diodes that do not emit light increases causing increased flicker extent
Solution Approach 1:
By segmenting the high-threshold-voltage string into multiple parallel strings with lower threshold voltages, the patent ensures that more micro-diodes conduct and emit light during each AC cycle. This reduces the proportion of non-conducting micro-diodes and minimizes flicker, while maintaining the ability to operate from mains voltage through the parallel configuration.
Solution Approach 2:
The patent changes the electrical parameters of the circuit by altering the connection configuration between series and parallel. This parameter change reduces the effective threshold voltage during operation, allowing micro-diodes to conduct at lower voltage levels and reducing flicker, while the overall system remains compatible with mains voltage through the parallel string architecture.
3Speed
If the frequency of AC voltage source is low, then the device can operate with standard mains frequency, but the flicker extent of micro-diode is increased
Solution Approach 1:
The patent segments the circuit into multiple parallel strings that can conduct at lower voltage thresholds. This segmentation effectively increases the duty cycle of light emission at standard mains frequency, reducing the perceived flicker by ensuring more continuous operation of the micro-diodes even at lower frequencies.
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 enhances light emitting efficiency, reduces flicker, and increases the power factor, enabling the AC light emitting device to operate effectively with AC voltage sources while minimizing power wastage.
Implementation Method 1
A light emitting diode (LED) has the high endurance, the long lifetime, the light and handy property and the low power consumption
Data Source
AI summary
An alternating current (AC) light emitting device includes an AC light emitting diode (LED) module and a waveform modulation unit. The AC LED module includes at least two sets of micro-diodes. The waveform modulation unit coupled between the AC LED module and an AC voltage source modulates a waveform of the AC voltage source.