Telephone equipment has traditionally been housed in large buildings, sheds and outdoor cabinets. The cooling of these facilities has been carried out using traditional methods. However, in many of the new systems being developed and deployed such as broadband ISDN, cellular and/or cable, heat dissipation densities will increase substantially [1]. Furthermore, the introduction … [Read more...]
Thermal management of telecommunications cabinets
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...]
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...]
Thermal control of space electronics
Introduction Telecommunication satellites are all based on the same overall design usinga 3 axis stabilization process, in which the North and South panels act asradiators and so ensure heat removal. This basic principle is illustrated in Figure 1. The ever-increasing demandfor national and international space-based communications in parallel with theevolution of space … [Read more...]
An introduction to thermoelectric coolers
Figure 1: Cross Section of a Typical TECouple Introduction Thermoelectric coolers are solid state heat pumps used in applications wheretemperature stabilization, temperature cycling, or cooling below ambient arerequired. There are many products using thermoelectric coolers, including CCDcameras (charge coupled device), laser diodes, microprocessors, blood analyzersand portable … [Read more...]
