LED Lamp Driver With Detection Circuit For Current Adaptation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing LED lamp systems with multiple lamps connected in parallel face challenges in adapting power distribution when a lamp fails, leading to potential overheating and reduced lifespan, as they lack a mechanism to adjust current output based on the number of functional lamps.

Innovation Solution

Incorporating a detection circuit within the LED driver that measures the current flowing through each lamp and adjusts the current setting resistance to match the number of functional lamps, using a combination of resistors and transistors to dynamically adjust the output current, ensuring appropriate power distribution and preventing overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple LED lamps are driven in parallel with a fixed current driver, then the system is simple and reliable, but when a lamp is removed the remaining lamps receive excessive current which reduces their lifetime

Engineering Contradiction:
ImproveLED lamp lifetimeVSAvoiddriver circuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the driver circuit continuously monitors the current flowing through each LED lamp and automatically adjusts the total current output based on the number of connected lamps. This feedback loop ensures that when a lamp is removed, the driver detects the change and reduces the current to the remaining lamps, preventing overheating and extending their lifetime while maintaining system reliability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent transforms the static fixed-current driver into a dynamic system that can adapt its current output in real-time. The driver circuit incorporates adjustable current setting resistances that can be dynamically modified based on the detected number of connected lamps, allowing the system to optimize performance and protect LED lifespan without requiring complex manual reconfiguration.

Inventive Principle:
Principle #15Dynamics

2Illumination intensity

If the driver current is increased to compensate for removed lamps, then the remaining lamps maintain brightness, but the increased current reduces the lamp lifetime and causes overheating

Engineering Contradiction:
Improvelamp brightnessVSAvoidlamp lifetime
Core Design Contradiction:
Illumination intensityVSDuration of action of stationary object

Solution Approach 1:

The driver circuit uses feedback from current sensors to detect when a lamp is removed and automatically adjusts the current distribution to maintain appropriate brightness levels without exceeding thermal limits. The system monitors lamp status and modulates the current output to balance illumination requirements with thermal management, preventing the runaway current increase that would otherwise occur.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the electrical parameters (current magnitude) dynamically based on the operational state of the system. When lamps are removed, the driver modifies the current setting resistances to adjust the current parameter to an optimal value that maintains sufficient brightness while staying within safe thermal operating limits, thereby extending lamp lifetime.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If additional elements are added to identify the number of connected lamps, then the driver can adapt power output, but the system requires pairing drivers and lamps and cannot adapt when lamps fail

Engineering Contradiction:
Improvepower adaptation capabilityVSAvoidsystem configuration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent enables the driver system to self-diagnose and self-adjust by incorporating detection circuits that automatically identify the number of connected lamps without requiring external configuration or pairing information. The system performs self-testing through current measurement and automatically reconfigures the current output, eliminating the need for manual driver-lamp pairing and providing automatic adaptation when lamps are removed or fail.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses feedback from built-in detection circuits to automatically determine the operational status and number of connected lamps. This feedback mechanism allows the driver to adapt its power output dynamically without requiring pre-configuration or external input, providing versatile power adaptation while maintaining simple system architecture.

Inventive Principle:
Principle #23Feedback

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

This solution effectively adjusts the output current to match the number of connected lamps, preventing overheating and extending the lifespan of remaining LED lamps by dynamically adjusting the resistance based on the presence or absence of each lamp, thereby ensuring safe operation and maintaining performance standards.

Implementation Method 1

The detection circuit is adapted to detect presence or absence of each of the plurality of LED lamps by measurement of a respective LED current flowing through each of the LED lamps

Methodology Applied
Scientific EffectElectrical current measurement: Ohm's Law

Implementation Method 2

a current setting resistance circuit for setting a maximum value of the LED driving current

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentEP3491890B1LED lamp(s) with single channel driver
Publication Date: 2021.01.13 SIGNIFY HOLDING BV
  • EP3491890B1 patent drawingFigure 1
  • EP3491890B1 patent drawingFigure 2
  • EP3491890B1 patent drawingFigure 3

AI summary

A light emitting diode (LED) apparatus is configured for driving multiple LED lamps in parallel. The light emitting diode apparatus includes at least one of the LED lamps, and a detection circuit (151, 152) that detects presence of each of the LED driver circuit (140). The LED driver circuit adjusts power and/or current to the detected LED lamps based on the detection of presence.