LED Triad Drive System Reducing Wiring Complexity

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Solution Overview

Problem

The high wiring complexity and cost associated with controlling triads of red, green, and blue LEDs in color controllable applications, such as automotive interior lighting, due to the need for multiple wires, which is a deterrent in cost-effective implementations.

Innovation Solution

A drive system that uses a single controller to power LED triad modules with integral encoding of hue and intensity information, utilizing a four-phase encoding sequence over a pair of conductors, allowing each module to decode and activate LEDs to produce desired colors and intensities, thereby reducing wiring requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If four wires are used to control LED triad for color control, then color control capability is achieved, but wiring complexity and cost increase

Engineering Contradiction:
Improvecolor control capabilityVSAvoidwiring complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple control functions into a single wire by encoding drive current instructions using variable resistance values. Instead of using separate wires for red, green, and blue LED control, the system merges all control signals into one wire where different resistance values represent different color combinations and intensity levels, thereby reducing wiring complexity while maintaining color control capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the control parameter from discrete wire connections to continuous resistance value modulation. By varying the resistance along a single control wire, the system can dynamically adjust the drive current distribution among red, green, and blue LEDs, enabling color control without increasing wiring complexity. This parameter change allows one wire to carry multiple control functions simultaneously

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If two wires are used to power LED triad module, then wiring complexity is reduced, but reliable power supply and control become challenging

Engineering Contradiction:
Improvewiring complexityVSAvoidpower supply reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent employs periodic modulation of the control signal to distinguish between power delivery and control instructions. The system uses alternating phases where one phase delivers power through the second wire while the other phase carries control signals through the first wire. This periodic action allows the two-wire system to reliably perform both power supply and control functions without interference, maintaining reliability while reducing wiring complexity

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent ensures continuous and reliable operation by maintaining constant power delivery through one wire while superimposing control signals on the other wire. The power supply remains uninterrupted while control instructions are continuously transmitted through resistance modulation, ensuring both power reliability and control accuracy throughout system operation

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP2157833B1Low-cost drive system for a led triad
Publication Date: 2018.10.10 DELPHI TECHNOLOGIES INC
  • EP2157833B1 patent drawingFigure 1
  • EP2157833B1 patent drawingFigure 2
  • EP2157833B1 patent drawingFigure 3A~3B

AI summary

A drive system (10) for powering LED triads (66, 68, 70) includes a controller (12) for supplying power to one or more LED triad modules (14) with integral encoding of the desired hue and intensity information (22, 24). The LED triad modules (14) each include an LED triad (66, 68, 70) and decoding circuitry (72-82) for activating the individual LED elements of the triad (66, 68, 70) according to the encoded hue and intensity information. In the illustrated configuration, the controller (12) supplies power to the LED triad modules (14) over a pair of conductors (16a, 16b), and the supplied power is modulated using a four-phase encoding sequence that is decoded by the decoding circuitry (72-82) of each LED triad module (14) so that each LED triad module (14) produces light of the desired hue and intensity.