Engineering, 20.11.2020 17:10, QuestionAsker4356
An electronic device, such as a power transistor mounted on a finned heat sink, can be modeled as a spatially isothermal object with internal heat generation and an external convection resistance. (a) Consider such system of mas M, specific heat c, and surface area As, which is initially in equilibrium with the environment at To. Suddenly, the electronic device is energized such that a constant heat generation Eg(W) occurs. Show that the temperature response of the device is: θ = exp RC where θ Ξ T-T(w): T(oo) is the steady-state temperature corresponding to t → oo; 0Ti T(; T: initial temperature of the device; R: thermal resistance 1/hAs; and C: thermal capacitance Mc. (b) An electronic device, which generates 60W of heat, is mounted on an aluminum heat sink weighing 0.31 kg and reaches a temperature of 100°C in ambient air at 20°C under steady- after the power is switched on?
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