Non-overlapping LED Driver Control for Miniaturization

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Solution Overview

Problem

Current multi-channel LED lighting systems face challenges in miniaturizing driver circuits due to limited space, requiring separate drivers for each channel, which compromises power factor and efficiency, and existing solutions either increase component size or reduce performance.

Innovation Solution

Implementing a method where light sources are activated in a non-overlapping sequence, with each source's end duration triggering the next, allowing for adjustable durations and eliminating the need for a global clock signal, thereby minimizing peak power and reducing driver size and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate drivers are used for each LED channel, then each channel can be independently controlled, but the total driver space and complexity increases beyond available limits

Engineering Contradiction:
Improveindependent channel controlVSAvoiddriver space and component count
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple independent LED channel drivers into a single integrated driver circuit. This single driver manages multiple LED channels by sequentially controlling them in non-overlapping time slots, thereby reducing the total number of driver components and saving space while maintaining independent control capability for each channel.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements periodic time-division multiplexing where each LED channel is activated in sequential non-overlapping time slots within a repeating cycle. This periodic activation allows a single driver to service multiple channels independently by allocating specific time periods to each channel, achieving both space reduction and independent control.

Inventive Principle:
Principle #19Periodic action

2Ease of operation

If PWM control is used for each channel, then precise power control is achieved, but peak power demand increases when multiple channels are active simultaneously

Engineering Contradiction:
Improvepower control precisionVSAvoidpeak power demand
Core Design Contradiction:
Ease of operationVSPower

Solution Approach 1:

The patent uses periodic time-division multiplexing to activate LED channels in sequential non-overlapping time slots. By ensuring that only one channel is active at any given moment within the PWM cycle, the peak power demand is limited to the maximum power of a single channel rather than the sum of all channels, while still maintaining precise PWM control for each channel.

Inventive Principle:
Principle #19Periodic action

3Area of stationary object

If driver circuits are miniaturized to fit limited space, then space constraints are met, but power factor and efficiency are compromised

Engineering Contradiction:
Improvedriver spaceVSAvoidpower factor and efficiency
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

The patent merges multiple driver functions into a single integrated driver circuit that occupies limited space. This consolidated design maintains high power factor and efficiency by using a single optimized power conversion stage rather than multiple separate drivers, thereby achieving miniaturization without sacrificing energy performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs periodic time-division multiplexing with non-overlapping time slots that allow a single driver to service multiple LED channels sequentially. This approach enables the use of a compact single-driver design that maintains high efficiency and power factor while fitting within limited space constraints.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2949182B2A method of controlling a lighting arrangement, a lighting controller and a lighting system
Publication Date: 2020.04.22 SIGNIFY HOLDING BV
  • EP2949182B2 patent drawingFigure 1~2
  • EP2949182B2 patent drawingFigure 3~4
  • EP2949182B2 patent drawingFigure 5~6

AI summary

A lighting controller and method has light sources which are activated for a respective lighting duration in a repeating non-overlapping sequence. The end of the lighting duration for one light source is detected for triggering the switching on of the next light source in the sequence. This provides non-overlapping control of the light sources and provides an efficient and easy to implement the required controller.