Search results
Results from the WOW.Com Content Network
In control theory, a bang–bang controller (hysteresis, 2 step or on–off controller), is a feedback controller that switches abruptly between two states. These controllers may be realized in terms of any element that provides hysteresis. They are often used to control a plant that accepts a binary input, for example a furnace that is either ...
Electrical hysteresis typically occurs in ferroelectric material, where domains of polarization contribute to the total polarization. Polarization is the electrical dipole moment (either C·m −2 or C·m). The mechanism, an organization of the polarization into domains, is similar to that of magnetic hysteresis.
If there is no hysteresis in unemployment, then for example if the central bank wishes to lower the inflation rate it may shift to a contractionary monetary policy, which if not fully anticipated and believed will temporarily increase the unemployment rate; if the contractionary policy persists, the unemployment rise will eventually disappear as the unemployment rate returns to the natural rate.
A family of hysteresis loops for grain-oriented electrical steel, a soft magnetic material. B R denotes retentivity and H C is the coercivity. The wider the outside loop is, the higher the coercivity. Movement on the loops is counterclockwise.
Hysteresis is an important concept in alternative stable state theory. In this ecological context, hysteresis refers to the existence of different stable states under the same variables or parameters. Hysteresis can be explained by "path-dependency", in which the equilibrium point for the trajectory of "A → B" is different from for "B → A ...
A nonlinear dynamical system exhibits chaotic hysteresis if it simultaneously exhibits chaotic dynamics (chaos theory) and hysteresis.As the latter involves the persistence of a state, such as magnetization, after the causal or exogenous force or factor is removed, it involves multiple equilibria for given sets of control conditions.
blocked rotor test A test of an electric machine where the machine is energized but the shaft is prevented from turning. Blu-ray A type of optical disc written and read using a blue/violet laser. Bode plot A plot of the amplitude and phase frequency response of a system, where the actual response is approximated by straight line segments.
The hysteresis loop (P x versus E x) may be obtained from the free energy expansion by including the term −E x P x corresponding to the energy due to an external electric field E x interacting with the polarization P x, as follows: