Absorption coefficient of film capacitance

Film capacitors are ubiquitous in our lives. It is widely used, such as our common air conditioners, refrigerators, washing machines, water heaters and so on. Today editors take a look at film capacitors, what is the absorption coefficient of film capacitance, the effect of film capacitance absorption coefficient and abnormal situation. Get to know the progress of the editor together.

A film capacitor is a capacitor that uses metal foil as an electrode to wrap it and polyethyl, polypropylene, polystyrene, or polycarbonate plastic films, reduplicated from both ends and rolled into a cylindrical structure. The absorption coefficient of the film capacitance of polypropylene is very small, and the tangent TG sigma of capacity and loss angle is very small with the temperature, and the dielectric strength increases with the temperature. This is one of his characteristics, which is difficult for other capacitors to have. So what is its absorption coefficient? This is a numerical value used to describe the dielectric absorption of a film capacitor, which we call the absorption coefficient, which is related to the three of the dielectric, the dielectric polarization and the absorption of the capacitor. This coefficient is not the same, different manufacturers, different types of batch will be different, and even the same manufacturer model batch production of each film capacitance is likely to be different.

The dielectric absorption effect of the film capacitor determines the low frequency characteristics of the capacitor. The smaller the absorption coefficient is, the better the film capacitor is, and the charge and discharge of the capacitor is faster. In the absolute ideal state, if the absorption coefficient can be 0, the dielectric (insulator) has no polarization under the effect of the applied electric field, the surface of the dielectric has no traction binding force on the charge, and the charge discharge response of the capacitor is not lagging. Of course, this is the ideal state, in fact, the current technology can not be achieved.

If the absorption coefficient is too large, the hysteresis of the capacitor charge and discharge response is serious, the time constant of the ultra low frequency smooth filter is larger, the zero point of the DC amplifier is disturbed, the unidirectional drift, the increase of the power circuit ripple, and so on will happen, so the absorption coefficient of the film capacitance should be smaller and better.