LED Illumination Power Compensation Circuit for Voltage Fluctuation
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Solution Overview
Problem
LED illumination devices are sensitive to fluctuations in commercial AC power voltage, leading to inconsistent brightness and flickering due to variations in peak voltage, which affect performance across different regions.
Innovation Solution
An LED illumination device with a power compensation function that includes a rectifier, power compensator, voltage detector, and constant current source, which adjusts the reference voltage based on detected changes in rectified voltage to maintain consistent current flow and brightness, using a multiplexer and operating mode selector to control groups of LEDs and a protection circuit to prevent overvoltage and overcurrent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If LED illumination devices are directly connected to commercial AC power without power compensation, then the device structure is simple, but the brightness becomes inconsistent and flickering occurs due to voltage fluctuations
Solution Approach 1:
The patent implements a feedback mechanism where a detector continuously monitors the rectified voltage level and provides this information to a power compensator. The power compensator adjusts the reference voltage based on the detected voltage variations, creating a closed-loop control system that maintains consistent LED brightness despite AC power fluctuations.
Solution Approach 2:
The patent dynamically changes the reference voltage parameter based on detected rectified voltage levels. When voltage fluctuations are detected, the power compensator modifies the reference voltage to compensate for these changes, thereby maintaining stable current flow through the LEDs and consistent illumination output.
2Reliability
If a power compensator with detector and reference voltage generator is added, then brightness consistency is improved, but the device complexity increases
Solution Approach 1:
The power compensator circuit performs multiple functions using a unified structure: it detects voltage variations, generates adjusted reference voltages, and controls current flow through the LEDs. This multi-functional approach reduces the need for separate dedicated components for each function, thereby limiting the increase in overall device complexity while achieving improved reliability.
Solution Approach 2:
The patent introduces a reference voltage generator as an intermediary component between the detector and the constant current source. This intermediary processes the detected voltage information and translates it into appropriate reference voltage adjustments, allowing the system to achieve reliable brightness control without requiring direct complex interactions between all components.
3Illumination intensity
If the reference voltage is adjusted to compensate for voltage changes, then brightness consistency is maintained, but the risk of overvoltage and overcurrent increases
Solution Approach 1:
The patent implements dynamic control of the reference voltage through the power compensator, which continuously adjusts the reference voltage level based on real-time detection of rectified voltage conditions. This dynamic adjustment allows the system to compensate for voltage drops while automatically reducing the reference voltage when input voltage is high, thereby preventing overvoltage and overcurrent conditions while maintaining brightness uniformity under normal operating conditions.
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 solution ensures uniform brightness and minimizes power output variations due to voltage changes, protecting the device from excessive voltage and current, thereby maintaining consistent illumination regardless of regional voltage deviations.
Implementation Method 1
a rectifier for converting an AC voltage signal to a rectified voltage signal
Implementation Method 2
a light emitting device including a plurality of LEDs connected in series
Data Source
AI summary
A light emitting diode (LED) illumination device having a power compensation function is provided. The illumination device includes a light emitting unit including a plurality of LEDs connected in series, a rectifier for rectifying input AC power to provide a rectified voltage to the light emitting device, and a power compensator for detecting a change in the rectified voltage provided to the light emitting device and compensating a current provided to the light emitting device according to the detected change in the rectified voltage.