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The thermodynamic limit is essentially a consequence of the central limit theorem of probability theory. The internal energy of a gas of N molecules is the sum of order N contributions, each of which is approximately independent, and so the central limit theorem predicts that the ratio of the size of the fluctuations to the mean is of order 1/N 1/2.
Another type of thermal switch is a PTC (Positive Temperature Coefficient) thermistor; these thermistors have a "cutting off" temperature at which the resistance suddenly rises rapidly, limiting the current through the circuit. When used in conjunction with a thermistor relay, the PTC will switch off an electrical system at a desired temperature.
The high limit exists for the sake of efficiency and safety. The boiler will also fire (regardless of thermostat state) when the boiler water temperature goes below a range around the low limit, ensuring that the boiler water temperature remains above a certain point. The low limit is intended for tankless domestic hot water; it ensures that ...
Temperature determines the statistical occupation of the microstates of the ensemble. The microscopic definition of temperature is only meaningful in the thermodynamic limit, meaning for large ensembles of states or particles, to fulfill the requirements of the statistical model. Kinetic energy is also considered as a component of thermal energy.
For the high-temperature limit and series expansions of the hyperbolic functions, the above is simplified as α S,vib = (ΔS vib /q) = (k B /q)Σ i (-Δω i /ω i). The Seebeck coefficient derived in the above Onsager formulation is the mixing component α S,mix , which dominates in most semiconductors.
Like the BaTiO 3 thermistor, this device has a highly nonlinear resistance/temperature response useful for thermal or circuit control, not for temperature measurement. Besides circuit elements used to limit current, self-limiting heaters can be made in the form of wires or strips, useful for heat tracing. PTC thermistors "latch" into a hot ...
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Hence, the regulated temperature is like a sliding mode of the variable structure system setup by the bang–bang controller. Symbol for a bang–bang control. In control theory, a bang–bang controller (hysteresis, 2 step or on–off controller), is a feedback controller that switches abruptly between two states.