Dynamic LED Driver Circuit Topology for Flicker Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LEDs connected in series and subjected to varying input voltages experience flickering, leading to reduced utilization and light output efficiency when AC power is directly applied, as the ON/OFF state of each LED is dependent on voltage magnitude, resulting in inefficient power conversion and light output.
Innovation Solution
An LED driving device that converts AC power to DC using a bridge diode and dynamically adjusts the number of parallel and serial connections based on voltage levels and current ripple, incorporating bypass units to manage current flow and prevent reverse current, thereby improving power factor and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If AC power is directly applied to series-connected LEDs, then the circuit complexity is reduced and no additional rectifying unit is needed, but the LEDs experience flickering and reduced utilization rate due to voltage-dependent ON/OFF states
Solution Approach 1:
The patent applies dynamics by making the connection configuration between LED groups changeable based on input voltage levels. The switching unit dynamically reconfigures the circuit from series to parallel connections when voltage drops, ensuring LEDs remain in ON state and preventing flickering while maintaining simplicity without requiring additional rectifying units.
Solution Approach 2:
The patent changes the electrical connection parameter (series/parallel configuration) based on voltage magnitude. When input voltage falls below a threshold, the switching unit changes the connection state to parallel, allowing LEDs to operate reliably across varying voltage conditions and maintaining high utilization rate without complex rectification circuitry.
2Device complexity
If AC power is directly applied to series-connected LEDs, then the device structure is simplified, but light output efficiency is reduced due to flicker phenomenon and repeated ON/OFF states
Solution Approach 1:
The patent uses dynamic reconfiguration of the LED group connections based on voltage levels. The switching unit detects voltage drops and transitions from series to parallel connections, preventing the flicker phenomenon and maintaining stable light output efficiency without adding complex device structure or rectifying units.
Solution Approach 2:
The patent converts the harmful voltage drop effect into a beneficial control mechanism. Instead of viewing voltage drops as problematic, the system uses them to trigger parallel connection mode, which actually improves LED reliability and maintains efficiency while keeping the device structure simple.
3Productivity
If the number of LED groups in parallel is increased to improve current capacity, then the LED utilization rate increases, but the circuit complexity and voltage sensitivity increase
Solution Approach 1:
The patent applies dynamic switching to manage the balance between LED utilization and circuit complexity. The system can reconfigure between series and parallel connections based on voltage conditions, allowing high utilization when voltage is sufficient while maintaining simplicity when voltage drops, without requiring fixed complex 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 enhances LED utilization and light output efficiency by automatically adjusting connection states and current distribution, ensuring consistent power delivery and minimizing flickering, thus improving overall power factor and efficiency.
Implementation Method 1
AC power is converted into DC power through a bridge diode
Data Source
AI summary
Disclosed is a light emitting device having a configuration that, when a magnitude of an input voltage is greater than a minimum light emitting voltage, all light emitting devices are turned on regardless of the magnitude of the voltage. As the magnitude of the voltage is smaller, the light emitting devices are connected in parallel. As the magnitude of the voltage is greater, the light emitting devices are serially connected.