The hysteresis is a property of biological, physical and other systems in which the instant response to influences depends on their current state, and on time interval the behavior of a system is defined by its background. A loop of a hysteresis is called the schedule showing this property.
Existence of an acute-angled loop on graphics is caused by dissimilarity of trajectories between the next distances and also effect of "saturation". A hysteresis often confuse with lag effect, however it not the same. The lag effect is such behavior model which designates the constant, uniform and monotonous resistance of a system to changes of its state.
Hysteresis in physics
In physics this property of systems is presented by three main versions: magnetic, ferroelectric and elastic hysteresis.
Magnetic hysteresis – the phenomenon which reflects dependence of a vector of tension of magnetic field and a vector of magnetization in substance. And both from the enclosed external field, and from background of a concrete sample. Existence of permanent magnets is caused by this phenomenon.
The model of a loop represents a certain cycle which sends some properties for repeated check and coordination, and uses some further. The selective character depends on properties of a concrete system.
Ferroelectric hysteresis – the changing dependence of polarization of a ferroelectric material on cyclic change of external electric field. An elastic hysteresis – behavior of the elastic materials capable to keep and lose deformation under the influence of big pressure. This phenomenon causes anisotropy of mechanical characteristics and high mechanical qualities of the forged products.
Hysteresis in electronics
In electrical equipment and electronics devices which use various magnetic interactions use property of a hysteresis. For example, magnetic data carriers or Schmitt's trigger. This property needs to be known to use it for suppression of noise at the time of switching of certain logical signals (a tinkling sound of contacts, fast fluctuations).
The elastic hysteresis happens two types: dynamic and static. In the first case the schedule will represent constantly changing loop, in the second – uniform.
In all devices of electronic type the thermal hysteresis is observed. After the device was heated, and then cooled, its characteristics do not accept former value. It occurs because unequal thermal expansion of cases of chips, kristalloderzhatel, printed circuit boards and crystals of semiconductors causes the mechanical tension remaining and after cooling. This phenomenon in precision sources of basic tension which are used in measuring converters is the most noticeable.