Lamp Operating Device Impedance Detection Circuit

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Solution Overview

Problem

Existing operating devices for light sources, particularly LED converters, require additional logic and data interfaces in the SELV area for user-defined settings, increasing costs and complexity, and lack flexibility in adjusting output currents without a data interface.

Innovation Solution

An operating device with a primary-side circuit and a secondary-side circuit, where the secondary side has a selection device with adjustable impedance, allowing the control device on the primary side to detect and respond to user-defined impedance values without separate logic or data interfaces, using a transformer and an independent inductor for energy transfer and impedance detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate logic and data interfaces are provided in the SELV area for detecting impedance values, then the operating device can recognize user-defined settings, but the device complexity and costs increase

Engineering Contradiction:
Improvecapability to recognize user-defined impedance settingsVSAvoidcomplexity of separate logic and data interfaces in SELV area
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the logic for detecting impedance values from the SELV area and relocates it to the non-SELV area. The secondary side now only contains passive impedance elements (resistors, capacitors, inductors) that can be set by the user, while the active detection logic resides on the primary side where it can communicate with control devices without requiring data interfaces across the SELV barrier.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent makes the primary-side circuitry universal by enabling it to perform both power conversion functions and impedance detection functions. The same primary-side circuit that converts power also detects the impedance values set on the secondary side, eliminating the need for separate dedicated detection logic in the SELV area.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If setting elements are provided in the SELV area for safety reasons, then safety requirements are met, but additional costs and effort are required for evaluation logic and data interfaces

Engineering Contradiction:
Improvesafety compliance with SELV separationVSAvoidmanufacturing effort for evaluation logic and data interfaces
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the evaluation logic from the SELV area and places it in the non-SELV area. Setting elements (impedance components) remain in the SELV area to maintain safety compliance, but the logic that reads and evaluates these settings is moved to where it can access them without requiring data interfaces across the SELV barrier.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses the transformer as an intermediary to transfer information about impedance settings from the SELV area to the non-SELV area without requiring data interfaces. The transformer enables galvanic isolation while still allowing the primary-side circuitry to detect the impedance values set on the secondary side through electrical coupling.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If no data interface is provided, then costs and complexity are reduced, but the operating device lacks flexibility in adjusting output currents

Engineering Contradiction:
Improvereduction of data interfaces and logicVSAvoidflexibility in adjusting output currents
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent replaces electronic data communication (data interfaces) with electromagnetic coupling through the transformer. Instead of using digital data interfaces to communicate impedance settings from the SELV area to the control device, the system uses the transformer's electromagnetic field to transfer this information, eliminating the need for data interfaces while maintaining full adjustability.

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 flexible adjustment of output currents and operating parameters based on detected impedance values, reducing costs and complexity by eliminating the need for separate logic and data interfaces, while maintaining safety through galvanic isolation.

Implementation Method 1

The galvanic separation or potential separation is required for safety reasons in the case of operating devices for lamps, in order to separate an SELV area from areas with a higher supply voltage, in particular mains voltage, by means of a so-called potential barrier or SELV barrier

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

A further inductor that is independent of the transformer and is inductively coupled to the impedance

Methodology Applied
Scientific EffectInductive coupling: Electromagnetic Induction

Data Source

PatentEP2842391B1Operating device for a lamp and method
Publication Date: 2017.08.16 TRIDONIC GMBH & CO KG
  • EP2842391B1 patent drawingFigure 1
  • EP2842391B1 patent drawingFigure 2~3
  • EP2842391B1 patent drawingFigure 4~5

AI summary

The invention relates to an operating device (2) for a lamp (3), the operating device (2) comprising a primary-side circuit (7) having a control device (14) for controlling the operating device (2), and a secondary side (8), which is electrically isolated from the primary side circuit (7) and which has an output (35) for supplying energy to the lamp (3). The secondary side (8) comprises a selection device having an impedance (15) that can be set to a plurality of different impedance values. The control device (14) is designed to recognise the set impedance value in accordance with a measured value (idet) detected in the primary-side circuit (7) and to control the operating device (2) in accordance therewith.