Limited Flicker LED String with Segmented Rectification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Decorative LED strings operating on AC power exhibit noticeable flicker due to sinusoidal voltage alternation, and existing solutions either increase cost and complexity or require non-standard components and enclosures, which detract from their decorative value and size-sensitive applications.
Innovation Solution
A limited flicker LED string design that provides full-wave rectification to most LEDs while half-wave rectifying the first and last two LEDs, minimizing visible flicker without additional enclosures or non-standard components, by integrating rectifying diodes within lamp sockets and using alternative wiring connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If full-wave rectification is applied to all LEDs using a bridge rectifier, then flicker is reduced significantly, but an external enclosure is required which adds cost and complexity
Solution Approach 1:
The patent divides the LED string into multiple series circuits, with different rectification approaches applied to different segments. Specifically, the first and last series circuits receive half-wave rectified power while intermediate circuits receive full-wave rectified power, eliminating the need for a single external enclosure housing all rectification components.
Solution Approach 2:
Different rectification methods are applied to different parts of the LED string based on their specific requirements. The end LEDs (first and last series circuits) use half-wave rectification while intermediate LEDs use full-wave rectification, optimizing both flicker reduction and circuit simplicity in different locations.
2Object-affected harmful factors
If a bridge rectifier is added to the power plug, then flicker is reduced, but cost and complexity increase significantly
Solution Approach 1:
Instead of placing a complete bridge rectifier in the power plug, the patent segments the rectification function across multiple locations along the LED string, with individual rectifying diodes distributed throughout the circuit to perform rectification locally where needed.
3Object-affected harmful factors
If split bridge rectification is used with diodes in plug and end connector, then flicker is reduced, but non-standard components are required
Solution Approach 1:
The patent further segments the rectification function by placing individual rectifying diodes at specific points within the standard end connector housing, rather than requiring a split bridge configuration across multiple non-standard components.
4Device complexity
If AC power is applied directly to series-connected LEDs, then the system is simple and reliable, but visible flicker occurs
Solution Approach 1:
The patent introduces rectifying diodes as intermediary components between the AC power source and the LED series circuits. These diodes convert portions of the AC waveform to DC, eliminating flicker while maintaining the simplicity of series-connected LED operation.
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 design significantly reduces visible flicker, enhances brightness, and maintains a clean appearance and cost-effectiveness by eliminating the need for external enclosures and non-standard components, while allowing for standard power plugs and connectors, making the LED string more suitable for decorative and general use.
Implementation Method 1
The plurality of rectifying diodes provides full-wave rectification of the AC power to the LED series and half-wave rectification of the AC power to the first and second pair of LEDs
Implementation Method 2
The plurality of rectifying diodes provides full-wave rectification of the AC power to the LED series and half-wave rectification of the AC power to the first and second pair of LEDs
Implementation Method 3
A first pair of light emitting diodes (LEDs) and a second pair of LEDs, a plurality of LEDs electrically connected in series
Data Source
AI summary
A limited flicker decorative light-emitting diode (LED) string includes a power plug adapted to connect to an alternating current (AC) power source and supply AC power to the LED string, a first pair of LEDs and a second pair of LEDs, a plurality of LEDs electrically connected in series to form an LED series, and a plurality of rectifying diodes. The plurality of rectifying diodes provides full-wave rectification of the AC power to the LED series and half-wave rectification of the AC power to the first and second pair of LEDs.