When time enters the equations, the ability of a material to store or release heat becomes a crucial parameter. This issue's technical data column is devoted to a basic understanding of thermal capacitance. Thermal capacity (or heat capacity) is defined as: Cth = V � � cp [J/K] where: V =Volume (m3) = Density (kg/m3) cp = Specific heat (J/kgK) at constant pressure (the … [Read more...]
Power Density Challenges Of Next Generation Telecommunication Networks
Despite the current downturn in the telecommunications industry, data transfer (i.e. network traffic) is continuing to grow at a 100% rate [1]. It is already projected that network traffic demand will reach tens of Tb/s in a couple of years from now (see predicted traffic demands from telecommunications analysts Ryan, Hankin & Kent, Figure 1). At the same time, network … [Read more...]
A Few Design Techniques On How To Reduce The Power
There will always be the need to get heat out of high power circuitry, but with a little extra design effort up front, we may be able to reduce overall power needs. Here are two techniques that can help do that. Turn Idle Circuits Off A circuit that is not always used can be turned off until needed. This is a technique widely used in battery powered electronics, but it can be … [Read more...]
Challenges In Thermal Control Of Military Electronics Systems
Thermal design engineers working in defense electronics are facing many challenges, some of which have been around for a long time and some that are more recent. Worldwide climatic extreme temperatures are reasonably constant and there are many military electronic systems that function in these extremes. As a result, there is significant design history available for … [Read more...]
Estimating Parallel Plate-Fin Heat Sink Thermal Resistance
As noted previously in this column, the trend of increasing electronic module power is making it more and more difficult to cool electronic packages with air. As a result there are an increasing number of applications that require the use of forced convection air-cooled heat sinks to control module temperature. An example of a widely used type of heat sink is the parallel plate … [Read more...]
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