[attachment=3599]

---

Presented By:
SNEHA BHAGCHANDANI student of B.Tech IVth year VIIth semester of Electrical Engineering of Govt. Engineering College Ajmer

---

ABSTRACT

As a part of curriculum prescribed for B. Tech degree of Engineering I have taken my practical summer training. The period of training was from May 18, 2009 to June 18, 2009.
The training report has been divided into 2 modules. First module concerns with the study and experiments performed on both Phase Change Materials (PCM) and Solar Radiation Chamber. These phase change materials are used to lower the operating temperature of electronic devices and/or circuits. Whereas Solar Radiation Chamber is that equipment in which experiments are conducted on PCM.
Second part of the training project report, deals with the Construction of a Temperature Controller. This circuit control temperature by controlling a fan fitted such that if temperature of room/chamber increases beyond a set limit it will automatically turn on the fan. Thus, temperature of that vicinity can be regulated.
ABOUT DEFENCE LABORATORY
JODHPUR

Defence Laboratory, Jodhpur was established on 16th May, 1959. DLJ is located at the gateway of Thar Desert of Rajasthan. It enhances the operational efficiency of troops in desert warfare and logistics support. The aim of the lab is to undertaken research studies in the following areas:
1 Camouflage & Low Observable Devices
2 Nuclear Radiation Management & Applications
3 Desert Environmental Science & Technologies
FIGURE 1
In addition to R&D activities in the above field, the lab conducts several training programs to the benefit of Services and Civil population, e.g. industrial radiography, NBC, radiation safety aspects, water desalination, quality, monitoring and desert meteorology. The lab has also been identified as a material development lab.
The objective of DEST or HMG (Heat Management Group) is the removal of unwanted heat from sources such as semiconductors without negatively affecting the performance or reliability of adjacent components. Thermal management addresses heat removal by considering the ambient temperature (and temperature gradients) throughout the entire product from an overall system perspective. Thermal removal solutions cover a wide range of options.
The simplest form of heat removal is the movement of ambient air over the device. In any enclosure, adding strategically placed vents will enhance air movement. The cooling of a critical device can be improved by placing it in the coolest location in the enclosure. When these simple thermal solutions cannot remove enough heat to maintain component reliability, the system designer must look to more sophisticated measures, such as heat sinks, fans, heat pipes, or even liquid-cooled plates. Thermal modeling using computational fluid dynamics (CFD) helps demonstrate the effectiveness of a particular solution.
The thermal management process can be separated into three major phases:
1. Heat transfer within a semiconductor or module (such as a DC/DC converter) package.
2. Heat transfer from the package to a heat dissipater.
3. Heat transfer from the heat dissipater to the ambient environment
For designers, a broad selection of materials is available to manage and control heat in a wide range of applications.
DEST department is still doing research work on developing such a material which can absorb that much extra heat. Phase-change thermal interface materials have been an important thermal management link. They don