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In the current setup of the electronics package, the heat generated by the transistors can only be lost through air convection. The temperature of the devicessurrounding, therefore, needs to be less than the allowable temperature of the device. At 150 degrees Celsius, the device is prone to damage. The introduced heat sink will however try to reduce the junction temperature for the device and ‘dump’ it in the surrounding media. Electronic device uses air as a medium.In a transistor; there exist connections between the casing and the junction and from the case to theheat sink. In addition, the contacts between the device and the sink usually contain a thin film, which, therefore, affects the heat transfer. All these features cause a temperature differential. They act as thermal resistances and usually each thermal resistance has a coefficient number always unique for each case and is expressed in temperature per watt. Because of this, there develops temperature differences between the collector junction and the ambient. This particular variable should however be kept at a minimum
1) Rearranging the transistors- In the current layout, the transistors are stacked together. This contributes to theaccumulationon heat thus increase in temperature. This proposed design will consider arranging the transistor and having some gap between them. The spacing ensures free circulation of air and heat loss from the transistor surfaces.
The material commonly used for heat sinks is aluminium with some fins fitted for more effective heat dissipation. The fins increase the surface area over which heat dissipation takes place.Since thecostis a major factor; the ultimate choice for this design will be aluminium.
The sink chosen have should have a flat surface to enhance good physical contact. This will ensure maximum heat transfer. Grooves that match the transistors contact will be createdon the heat sink block.
The heat sink will be fixed together with a
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The objectives of the course are as follows: 1. To attain skills of electrocardiogram measurements for patients with heart conditions 2. To acquire knowledge on reading and interpreting an electrocardiogram 3. To be able to evaluate and manage patient needs during electrocardiogram measurements 4.
Without education, people will live a primitive life that is bereft of reason, justice and truth. Conversely, with education, life has become more meaningful and simple. With education, we can now combat some deadly diseases, we can sleep in the comforts of our home, enjoy watching television or simply heat up dinner with a microwave oven.
Accordingly, it can enable learners to obtain tangible benefits and contribute to the sustainability of the entire community. Stating precisely, an effective curriculum aims to develop cognitive, emotional, humanistic and judgmental skills of the pupils. This enables them to pursue a promising career in their adulthood and also become a responsible citizen.
The exchange system is designed such that the composition of the coolant is 100% Freon 12. In that regard, the inlet temperature of the system is 240K. The design is also to have the outlet temperature of the 100% Freon 12 being 300 K. For the Freon, the designed pressure at the inlet is 7atm.
In particular, this paper attempts to assess the effectiveness of the various types of solar cells.
The two types of solar cells that have been used are the spherical solar cells and the ordinary planar cells. These are flat cells, which are manufactured from silicon
Such a crane is capable of loading and unloading containers from very wide ships. These ships are so big and capacious that they can not even pass through the Panama Canal. Normally, they can carry up to 18 containers in a row in their width. These are known as the largest cranes in the present age.
The author states that when designing prosthetic heart valves, care has to be taken to ensure that the different biomaterials used to design them, fit the peculiar blood flow requirements of the human body. The different biomaterials used in designing of these valves are carbon, titanium, alumina, polyurethane, and polyester.
This phenomenon of water evaporation on the free water surface of an indoor pool is a major contributor to the energy balance of thepools surrounding. Incase the total pressure of humid air which is on water surface and equal to sum of partial pressure of water