INTERNATIONAL JOURNAL FOR TRENDS IN ENGINEERING & TECHNOLOGY VOLUME 4 ISSUE 2 – APRIL 2015 - ISSN: 2349 - 9303
ARM Based Climate Controlled Wearable Jacket R.Naghalakshimi II year Student, M.E. Embedded Systems Technologies Sri Ramakrishna Engineering College Coimbatore, India nagramval@gmail.com
Dr. S. Jayanthy Professor, Department of ECE Sri Ramakrishna Engineering College Coimbatore, India sjayanthyabi@gmail.com
Abstract— Thermo-electric (TE) technology is used in both electricity generation and air-conditioning. The Thermo-electric coolers(TEC) uses Peltier effect which converts the electrical energy applied from the ends of the Thermo-electric module into the temperature difference. The main objective of the work is to design a highly reliable and wearable jacket that controls extreme temperatures say working in thermal power plants, within the jacket. The extreme temperatures can be monitored using temperature sensors placed on both sides of the Thermo-electric cooler module and controlled using ARM LPC2148 Microcontroller. In Industries, this jacket provides a more practical and safer solutions for human working under extreme temperatures. Furthermore, this jacket can also be applied as a good warmer one for human beings working in cold regions(say Polar regions). Index Terms— ARM7 LPC2148 Microcontroller, Heat dissipation, Monitoring and Controlling Temperatures, Peltier effect, Temperature Sensor, Thermo-electric Cooler (TEC) Module, Wearable Jacket. —————————— ——————————
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INTRODUCTION
Thermo-electric cooling is a way to remove thermal energy from a medium, device or component by applying a voltage of constant polarity to a junction between dissimilar electrical conductors or semiconductors. A thermo-electric cooling system typically employs a matrix of semiconductor pellets sandwiched in between two large electrodes. When a DC voltage source is connected between the electrodes, the negatively-charged side becomes cooler while the positively-charged side becomes warmer [3]. The negative electrode is placed in contact with the component, device or medium to be cooled, while the positive electrode is connected to a heat sink that radiates or dissipates thermal energy into the external environment. A Peltier cooler can also be used as a thermo-electric generator. When operated as a cooler, a voltage is applied across the device, and as a result, a difference in temperature will build up between the two sides ( the Peltier effect). When operated as a generator, one side of the device is heated to a temperature greater than the other side, and as a result, a difference in voltage will build up between the two sides (the Seebeck effect). A single-stage Thermo-electric cooler will typically produce a maximum temperature difference of 70 °C between its hot and cold sides. The more heat moved using a TEC Module, the less efficient it becomes, because the TEC Module needs to dissipate both the heat being moved, as well as the heat it generates itself from its own power consumption. The amount of heat that can be absorbed is proportional to the current and time [1]. In general, thermo-electric cooling is less efficient than compressor-based refrigeration. However, in situations where thermal energy must be transferred away from a solid or liquid on a small scale, a thermo-electric cooling may be more practical and cost-effective than a conventional refrigeration system [2]. Other advantages of the thermo-electric cooling include minimized cost, power consumption, portability, long operating life and minimal maintenance requirements.
Thermo-electric cooling is used in electronic systems and computers to cool sensitive components such as power amplifiers and microprocessors. The technology can also be useful in a satellite or space probe to moderate the extreme temperatures that occur in components on the sunlit side and to warm the components on the dark side [4]. So, Thermo-electric cooler modules can be implemented in the design of climate controlled wearable jacket which helps people working in extreme temperatures. The extreme temperatures can be monitored using temperature sensors placed at the top and bottom the thermo-electric cooler module and controlled using ARM7 LPC2148 Microcontroller embedded with the module. In order to control the heat dissipated at the hot side of the Thermoelectric cooler module, a small liquid pump and heat sink can be connected using Relay. To control the extreme temperatures and provide a temperature that is tolerable to people, a relay is connected to control the power supply of the Thermo-electric cooler module. Hence, the Thermo-electric cooler module makes an effective climate controlled wearable jacket which provides a more safer and practical solutions to people working in extreme temperatures. This module makes the design very cheap and reliable. The Climate Controlled Wearable jacket is implemented in a single system using a Thermoelectric cooler module along with a heat sink prototype. In this paper, Section II describes about the proposed Climate Controlled wearable jacket, system design, Programming in IDE, Thermo-electric cooler Module and Software algorithm. Section III displays the proposed system design. Section IV explains the various experimental results took at various instances. Finally, Section V deals with the conclusion and future work.
2 PROPOSED CLIMATE CONTROLLED WEARABLE JACKET 2.1 Existing System Currently, the Thermo-electric cooler modules are used in designing
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