Technical Design-in Guide Engine LLE G2 PRE KIT | 03-2020 | 1.2 | en
Thermal Aspects
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7.2. Passive cooling
Heat transfer from a heat source to the surrounding cooling medium (e.g. air) depends primarily on the difference in temperature, the
effective surface area and the flow rate of the cooling medium. The function of a heat sink is to increase the surface area over which
the heat can be dissipated. This lowers the thermal resistance.
A passive heat sink works mainly by convection. The surrounding air is heated, which makes it rise, and is replaced by cooler air.
Heat pipes can be used as an alternative to cooing with fans. If space is particularly tight, the heat is first conveyed away. The actual
heat sink is located at the other end of the heat pipe.
Benefits of passive cooling
7.2.1. Effect of cooling on the life of the modules
The modules of the LLE G2 PRE KIT system have been designed for operation with a passive heat sink and can be mounted directly
on such a suitable heat sink.
The life of the module depends to a large extent on the operating temperature. The more that the operating temperature can be
reduced by cooling, the longer the expected life of the module. If the permitted operating temperature is exceeded, however, the life
of the module will be significantly reduced.
7.2.2. Requirements for the heat sink
The modules must not be operated without a heat sink. The heat sinks must be dimensioned to provide adequate cooling capacity.
The necessary R value is decisive when selecting a suitable heat sink. This value depends on the thermal power loss of the module
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and the ambient temperature at which the module is to be operated. The R value of the heat sink must always be smaller than the
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required R value.
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Energy savings
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Silent
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No mechanical wear
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No maintenance
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NOTICE
Please check the information on the operating temperature and the requirements for cooling in the module data sheets.
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NOTICE
Please keep in mind that LLE G2 PRE KIT doesn´t support possibility to use active fans.