Figure 1. Thermal analog model of an OSP enclosure Introduction Over the past twenty years, telecommunications electronics have become increasingly decentralized - moving ever furtherfrom the controlled and protected environment of the Central Office intothe Outside Plant (OSP). The OSP environment contains rain and humidity,dust and pollutants, significant daily and annual … [Read more...]
Standardizing heat sink characterization for forced convection
Figure 1. Wind tunnel configuration Introduction While there has been a flurry of activity inliterature addressing the behavior of heat sinks in computer electronics,the reusability of the data presented in these papers has been somewhatlimited for two reasons: 1) The data presented is application specific. 2) There has never been a standard method for characterizing … [Read more...]
One-dimensional heat flow
The simplest heat flow situation is that described as “one-dimensional heat flow”. The Figure illustrates a one-dimensional heat flow situation. It shows heat flowing in one face of an object and out the opposite face. Each face is at a uniform temperature. There is no heat flow out of the sides of the object. The cross- sectional area of the object in the direction of heat … [Read more...]
Forced convection cooling of airborne electronics
Figure 1. AFT description Fin pitch = 25.01 per in = 985 per mPlate spacing, b = 0.200 in = 5.08 x 10-3 m Fin Length = 0.111 in = 2.8 x 10-3 m Flow passage hydraulic diameter 4rh = 0.004905 ft = 1.50 x 10-3 m Fin metal thickness = 0.004 in = 0.102 x 10-3 m Total heat transfer area/volume between plates, ß = 719.4 ft2 / ft3 = 2,360 m2 / m3 Fin area / total area = … [Read more...]
Calculating interface resistance
Figure 1. Ceramic Package - Aluminum Heat SinkAssembly Introduction The exposed surface area of many of today's high powered electronic packagesis no longer sufficient for the removal of the heat generated during normaloperation. Heat sinks are a commonly-used, low cost means of increasing theeffective surface area for dissipating heat by means of convective air cooling.While … [Read more...]
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