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The main objective of this work is design and investigations of a lamp with controllable spectral and power characteristics suitable for illumination of premises intended mainly for elderly people. With the advancement of modern science and medicine, the average lifespan increases significantly. This leads inevitably to an increase in the absolute number and the elderly people. As a person becomes...
The aim of this work is related to the development of efficient, low-cost active LED cooling systems for industrial applications in horticulture, poultry housings, dairy farms and others. Investigations and comparative analysis of different variants of LEDs' cooling by use of different types of water pipes were carried out to find an optimum thermal performance. Two types of water pipes — polyethylene...
The aim of this work is investigating the possibilities for creation of energy effective LED modules with special spectral characteristics and radiant flux, suitable for greenhouse applications. Combinations of different types of LEDs and LED modules are tested to achieve spectral power distribution proper for particular types of plants. Proper thermal management analysis and experimental investigations...
The article describes the design, construction and the implemented thermal management of a LED lamp for use in lighting of poultry housing. The required operational regimes and properties of such lamps are different than those suited for human use. Thus the spectral and power characteristics of the lamp are chosen appropriately so as to accommodate for the differences in vision of poultry. A particular...
The aim of the present work is the design and construction of LED lamp with tunable spectral characteristics. In order to achieve basic light property as spectral power distribution (SPD) of daylight at noon and late afternoon, particular mixture of LEDs with different spectral and power characteristics and proper control of the LEDs' operation are used. The differences in the LEDs' thermal properties...
Lighting in a poultry house is one of the significant factors affecting fowls' health, growth, behavior, productivity and overall costs. Birds have different spectral sensitivity compared to that of humans, which determines the need of specially designed luminaires. In order to provide an energy efficient luminaire matching fowls' spectral sensitivity, a selection of light emitting diode (LED) is...
Frequently the direct assessment of the LEDs' junction temperature as one of the main parameters to evaluate the extent of the thermal load is possible only under laboratory conditions. In this paper we present the development of a cheap and reliable experimental method to establish the junction temperature of high-brightness LED arrays under operating conditions. It is based on the insitu determination...
The aims of this work are connected with development of new method of LEDs' mounting onto the heat sink in lighting equipment. The technique involves usage of copper pins instead of standard MCPCBs. LEDs are soldered on copper pins. Mounting of LEDs demands boring holes in the heat sink and fixing copper pins into the holes by thermal conductive epoxy resin only. LED lamp is made using new technology...
In this work investigations are connected with development of method of LEDs' junctions' temperatures estimation at real operating conditions. Direct junction temperature determination is not possible and alternative methods have to be developed. Suitable, cheap and reliable method for direct estimation of LEDs' junction temperatures during operating of lighting equipment is proposed. It is realized...
Investigations are connected with design and application of thermally and cost effective rigid LED strips. Standard FR 4 PCB is used for making rigid strip and LEDs are soldered on it. Special copper pins soldered underneath LEDs contribute to low thermal resistance between LEDs and heat sink - like when MCPCBs are used. Application of this type low cost rigid LED strips allows decreasing operations...
Investigations deal with development of cost effective thermal management for power LEDs. The technique involves usage of FR4 based PCBs which cost less, but have greater thermal resistance than metal core printed circuit boards (MCPCB). The use of copper pins underneath LED thermal pad is a method to dissipate heat through an FR4 PCB into an appropriate heat sink. Temperature regimes of operation...
Investigation deals with LED's thermal management optimization in dependence of operating condition aided by application of infrared thermography. Thermal management calculations allow estimating temperature distribution on the LEDs, metal - core printed circuit boards (MCPCB) and heat sink but often real results may be different and experimental investigations are necessary. Good results are obtained...
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