LED Driver Voltage Booster Circuit for Flicker Reduction
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Solution Overview
Problem
Conventional electronic transformers cause LEDs to flicker and reduce brightness by turning them on and off twice per AC cycle, leading to visible flickering and decreased average brightness due to periodic voltage drops below the LEDs' forward voltage.
Innovation Solution
An LED driving system with a voltage booster circuit, comprising diodes and capacitors, that boosts the input voltage to maintain LED illumination during AC cycles, reducing 'dead' times and increasing the average forward current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional electronic transformers are used to power LED lighting systems, then the system is simple and low-cost, but the LEDs experience visible flickering and reduced average brightness due to turning on and off twice per AC cycle
Solution Approach 1:
The voltage booster circuit performs preliminary action by boosting the input voltage before it reaches the LED driver, ensuring that the voltage remains above the LED forward voltage threshold throughout the entire AC cycle. This prevents the LEDs from turning off during voltage dips, eliminating flickering while maintaining compatibility with conventional electronic transformers.
Solution Approach 2:
The voltage booster circuit acts as an intermediary component between the conventional electronic transformer and the LED driver. It mediates the voltage fluctuations from the transformer by boosting them to a stable level that prevents LED shutdown, thereby resolving the conflict between using simple transformers and achieving stable LED illumination.
2Loss of energy
If the input voltage drops below the LED forward voltage during AC cycles, then the system uses simple conventional power supplies, but the LEDs turn off periodically causing dead time and reduced average brightness
Solution Approach 1:
The voltage booster circuit performs preliminary voltage enhancement before the voltage drop occurs during AC cycles. By boosting the voltage in advance, it ensures that the LED driver receives sufficient voltage throughout the entire cycle, preventing periodic shutdowns and maximizing the LED on-time duration.
Solution Approach 2:
The voltage booster circuit enables continuous useful action by maintaining the input voltage above the LED forward voltage threshold throughout the entire AC cycle. This eliminates dead time periods where LEDs are off, ensuring continuous light output and maximizing the duration of useful illumination.
3Illumination intensity
If a voltage booster circuit is added to maintain LED illumination, then LED brightness and flickering are improved, but the device complexity and component count increase
Solution Approach 1:
The voltage booster circuit is designed with multi-functionality, serving both to boost voltage for LED drivers and to provide power factor correction. By combining multiple functions into a single circuit topology, it improves LED performance without proportionally increasing device complexity.
Solution Approach 2:
The voltage booster circuit utilizes parameter changes in the AC input voltage (specifically the voltage envelope) to its advantage by boosting the voltage during specific phases of the AC cycle. This approach extracts useful energy from the voltage variations rather than treating them as disturbances, improving efficiency while maintaining relatively simple circuitry.
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 significantly reduces visible flickering and increases LED brightness by approximately 21% while maintaining cost competitiveness and simplicity, without requiring complex external circuits or increased component counts.
Implementation Method 1
An LED driving system with a voltage booster circuit, comprising diodes and capacitors, that boosts the input voltage to maintain LED illumination during AC cycles
Data Source
AI summary
A circuit includes a driver configured to generate an output for driving one or more light emitting diodes. The circuit also includes a voltage booster configured to boost an input voltage provided to the driver when the voltage booster is coupled to a high-frequency pulsating alternating current (AC) voltage source that provides the input voltage. The voltage booster may include two first diodes coupled in series, two second diodes coupled in series, and first and second capacitors coupled in series. A first input voltage terminal may be coupled between the first diodes, and a second input voltage terminal may be coupled between the second diodes and between the capacitors. The voltage booster may be further configured to provide the input voltage to the driver without boosting when the voltage booster is coupled to a direct current (DC) or low-frequency AC voltage source that provides the input voltage.