causes collisions. The Coulombic attraction between Electrons and Protons means that these collisions transfer energy from electrons to lattice nuclei and back to electrons. The increase in energy is predominantly due to translational oscillations. These collective oscillations define the object’s Temperature. The more the atoms oscillate, the greater the likelihood that future collisions will occur, which leads to higher amplitude oscillations, and this feedback loop creates a condition known as Thermal Runaway. Thermal runaway continues until the temperature of the object rises so high that materials decompose into magic smoke and a variety of carcinogens.
The only way to stop this cyclic effect is to allow the lattice to transfer their energy somewhere else through some combination of three processes: conduction, convection, and radiation. Common language Temperature is the measure of the total kinetic energy of a group of molecules. Heat is the transfer of that energy from high-temperature (high energy) objects to low- temperature (low energy) objects. In everyday language, we call objects “hot” if when we touch them, energy transfers out of the object into our hands, and we call objects “cold” if when we touch them, energy transfers out of our hands into the objects.
heat energy out of your circuit or until something fails. Limit heat generation when you can, and when you can’t limit it, expel it from your design into the environment. Heat dissipation There are three passive methods of heat transport: Conduction, Convection, and Radiation. Conduction Conduction happens when objects are in direct contact. Heat energy transfers from the high temperature object to the lower temperature object. Convection Natural convection occurs when a high temperature object transfers heat to a surrounding lower temperature fluid, causing the fluid to expand, and in the presence of gravity, denser and colder fluid comes in and replaces the less-dense and warmer fluid in a cyclic process. Radiation Radiation occurs as atoms emit photons. The photon’s frequency depends on the temperature of the object. As photons leave the object, the parent atoms lose energy and temperature decreases. For better or worse,
Heat generation
Thermal runaway occurs when the heat entering a circuit is greater than the heat leaving a circuit. The temperature increases which leads to increased resistance. Resistance increases due to increasing temperature. This feedback loop eventually leads to temperatures high enough
Every common conductor is subject to Joule’s law of heating: , where P is “Power”, or the rate of heating, I is current, measured in Amperes, and R is the resistance, measured in Ohms. This is true of conductors that obey Ohm’s law, and PN junctions that don’t. If you want current to flow in your circuit, as electronic engineers are wont to do, your design will generate heat and the temperature of the PCB will rise until the rate of heat energy into the circuit matches the rate of
melt or sublimate the conductor and break the circuit.
we get technical
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