Decentralized Lighting Bus Participant Voltage Control

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Solution Overview

Problem

In bus-capable lighting systems, particularly those using the Digital Addressable Lighting Interface (DALI), the existing decentralized power supply designs face challenges in safely connecting to a live bus in idle state, risking overload and damage due to potential excessive current draw during the start procedure, especially when multiple supply units are parallel-connected.

Innovation Solution

A decentralized bus-capable lighting system participant with a control circuit that detects voltage changes upon power supply connection and short-circuiting, ensuring polarity detection and monitoring the bus voltage recovery speed to prevent excessive current draw, featuring a supply unit that can selectively connect to the bus and manage current consumption within safe limits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple DALI supply units are operated in parallel to increase power supply capacity, then the power supply capability is improved, but the current draw may exceed the maximum current limit and damage bus devices

Engineering Contradiction:
Improvepower supply capabilityVSAvoidexcessive current draw
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The control circuit continuously monitors the bus voltage and detects changes that indicate the presence of other supply units. Based on this feedback, the control circuit adjusts the output current of the supply unit to ensure the total current draw remains within the maximum limit, preventing bus device damage while maintaining adequate power supply capability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Before a supply unit connects to the bus, the control circuit performs a preliminary detection phase during the start-up procedure wait time to sense the bus voltage and determine if other supply units are present. This preliminary action allows the supply unit to configure its output current appropriately before actually supplying power, preventing excessive current draw from the outset.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the bus voltage is monitored continuously to detect polarity changes and prevent overload, then the system reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvesystem reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control circuit performs voltage detection and polarity verification during the mandatory start-up procedure wait time before the bus becomes operational. This preliminary detection ensures that the supply unit is properly configured and will not cause polarity conflicts or overload conditions when it begins supplying power, thereby improving reliability without requiring complex continuous monitoring mechanisms.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3741191B1Device for a lighting network bus with decentralized power supply
Publication Date: 2024.11.27 TRIDONIC GMBH & CO KG
  • EP3741191B1 patent drawingFigure 1

AI summary

The invention relates to a bus-enabled lighting system participant having a voltage supply which can be selectively connected to supply a bus which carries voltage in the idle state. The participant has a control circuit which is designed to capture the change in the bus voltage as a result of at least one of the two following events: a.) the connection of the voltage supply, and/or b.) short-circuiting of the bus.