Development and analysis of a modular LED array light source

Mitterhofer, Stefan (author), Korošak, Žiga (author), Rojec, Žiga (author), Jankovec, Marko (author), Topič, Marko (author)

Light emitting diodes (LEDs) have experienced rapid technological development in the past decade, making them a winning alternative to conventional light sources in many applications. LED arrays allow precise control of the desired irradiance profile in a target area by adjusting the position and output power of individual LEDs. However, despite increased efficiency, many LEDs still transform a large proportion of the input electrical power into heat, requiring an efficient cooling system. This paper presents a modular LED array light source mounted on a water-cooled aluminum plate. Novel electronic LED driver modules, connected via a serial communication bus in a daisy-chain topology, were developed with the ability to set the operating current of individual LEDs. A modular layout of cooling and mounting system and LED driver modules, as well as a specialized design for the LED soldering footprint, was able to house a variety of common commercial LEDs, enabling easy adjustment of the lighting system to the required application and size of the irradiated area. In a prototype of one plate containing 10 LEDs, individual LED radiance was optimized for a better irradiance homogeneity in the target area. Array characterization showed a low standard deviation of the irradiance of 1.8% and a good fit between measured and calculated irradiance. A test of the array at elevated temperatures showed moderate LED radiance degradation and a wavelength shift of the measured spectra after extended use.

• Language: English
• Keywords: LED, light sources, light emitting diode, lighting system, irradiance optimization, degradation
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FE - Faculty of Electrical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2020
• Number of pages: 16 str.
• Numbering: Vol. 7, iss. 4, art. 92
• PID: 20.500.12556/RUL-134463
• UDC: 621.383.51
• ISSN on article: 2304-6732
• DOI: 10.3390/photonics7040092
• COBISS.SI-ID: 42913027
• Publication date in RUL: 17.01.2022

Record is a part of a journal

• Title: Photonics
• Shortened title: Photonics
• Publisher: MDPI AG
• ISSN: 2304-6732
• COBISS.SI-ID: 523331609

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 01.12.2020

Secondary language

• Language: Slovenian
• Keywords: LED, svetlobni viri

Projects

• Funder: EC - European Commission
• Funding programme: H2020
• Project number: 721452
• Name: Photovoltaic module life time forecast and evaluation
• Acronym: SOLAR-TRAIN

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0197
• Name: Fotovoltaika in elektronika