Consider a power transistor encapsulated in an aluminum case that is attached at its base to...

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Consider a power transistor encapsulated in an aluminum case that is attached at its base to a square aluminum plate of thermal conductivity k = 240 W/m.K, thickness L = 8 mm, and width W = 24 mm. The case is joined to the plate by screws that maintain a contact pressure of 1 bar, and the back surface of the plate transfers heat by natural convection and radiation to ambient air and large surroundings at To Tsur = 30C. The surface has an emissivity of = 0.9, and the convection coefficient is h 108 W/m.K. The case is completely enclosed such that heat transfer may be assumed to occur exclusively through the base plate. = = I sur Transistor case Ts,c, Pelec Enclosure Base plate, (k,) Interface, Ac TS.P Air 001 Too, h = If the air-filled aluminum-to-aluminum interface is characterized by an area of Ac 2 10-4 m and a roughness of 10 m and the surface temperature of the case, Ts,c, is not to exceed 85C, determine the maximum allowable power dissipation, in W, and the associated surface temperature of the power transistor, Ts,p, in K. = 356.089 TS.P Imax = K W Consider a power transistor encapsulated in an aluminum case that is attached at its base to a square aluminum plate of thermal conductivity k = 240 W/m.K, thickness L = 8 mm, and width W = 24 mm. The case is joined to the plate by screws that maintain a contact pressure of 1 bar, and the back surface of the plate transfers heat by natural convection and radiation to ambient air and large surroundings at To Tsur = 30C. The surface has an emissivity of = 0.9, and the convection coefficient is h 108 W/m.K. The case is completely enclosed such that heat transfer may be assumed to occur exclusively through the base plate. = = I sur Transistor case Ts,c, Pelec Enclosure Base plate, (k,) Interface, Ac TS.P Air 001 Too, h = If the air-filled aluminum-to-aluminum interface is characterized by an area of Ac 2 10-4 m and a roughness of 10 m and the surface temperature of the case, Ts,c, is not to exceed 85C, determine the maximum allowable power dissipation, in W, and the associated surface temperature of the power transistor, Ts,p, in K. = 356.089 TS.P Imax = K W