KNX-DALI Interface Device with Opto-Coupler Isolation

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Solution Overview

Problem

Existing systems fail to effectively connect motion detectors on the KNX bus with luminaires connected to the DALI bus or mains, limiting their operation and control.

Innovation Solution

An interfacing device with a control stage, power supply stage, and voltage isolation stage connects the KNX bus to the DALI bus, enabling communication and control of luminaires through the DALI protocol, using a microcontroller and opto-couplers for isolation and overvoltage protection, or a relay for direct control when not using DALI.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a KNX motion detector is directly connected to control luminaires on the same KNX bus, then the system architecture is simple, but it cannot control luminaires connected to different bus systems (DALI bus or mains)

Engineering Contradiction:
Improvecompatibility with different bus systemsVSAvoidsystem architecture
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary device that acts as a bridge between the KNX bus and DALI bus systems. This intermediary contains a microcontroller that receives presence detection signals from the KNX bus and translates them into DALI protocol commands to control luminaires on the DALI bus, enabling cross-bus control without direct connection between detector and luminaires

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system is segmented into functionally independent modules: a KNX interface module for detection, a microcontroller for protocol translation, and a DALI interface module for control. This segmentation allows each module to operate independently while maintaining compatibility with different bus standards through standardized interfaces

Inventive Principle:
Principle #1Segmentation

2Reliability

If voltage isolation is implemented between KNX and DALI buses, then protection against overvoltages and electrical interference is improved, but device complexity increases

Engineering Contradiction:
Improveprotection against overvoltagesVSAvoidcircuit design
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Opto-couplers are used as intermediary components to transfer control signals between the KNX and DALI sides while providing electrical isolation. The opto-couplers convert electrical signals to optical signals and back, preventing direct electrical connection and thus protecting against overvoltages and ground potential differences

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct electrical connection with optical communication through opto-couplers. This substitution eliminates the need for galvanic isolation circuits while maintaining signal transmission, simplifying the isolation implementation compared to traditional electrical isolation methods

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enables seamless communication and control between KNX and DALI bus systems, optimizing lighting management with reduced no-load consumption and efficient power usage, while protecting against overvoltages and ensuring compliance with bus standards.

Implementation Method 1

the switched-mode power supply is a flyback converter-type assembly comprising a transformer with double primary winding and double secondary winding in series

Methodology Applied
Scientific EffectFlyback converter: Electromagnetic Induction

Implementation Method 2

The voltage isolation between the DALI and KNX buses is achieved by means of opto-couplers arranged on the connection lines

Methodology Applied
Scientific EffectOpto-coupling: Optical Fibre

Data Source

PatentEP2395817B1Interface device between a motion sensor for KNX bus and the lights using a DALI bus
Publication Date: 2020.02.19 HAGER CONTROLS
  • EP2395817B1 patent drawingFigure 1
  • EP2395817B1 patent drawingFigure 2~3
  • EP2395817B1 patent drawingFigure 4~5

AI summary

The device (2) has a controlling stage (3) for controlling lights. A supplying stage (4) supplies power to the controlling stage. A voltage isolation stage is arranged among the lights and a microcontroller. The controlling stage comprises a reception circuit receiving data from a digital addressable lighting interface bus and a transmission circuit transmitting data to the bus. The reception and transmission circuits are connected to the microcontroller via the isolation stage. The isolation stage comprises opto-couplers arranged on connection lines of the circuits.