What is the difference between polarized and non-polarized capacitors?
Issuing time:2020-04-17 15:04
Polarized electrolytic capacitors and non-polarized electrolytic capacitors have the same principle: they store and release charges; the voltage on the plate (here, the electromotive force accumulated by the charge is called voltage) cannot be changed suddenly.
The two media are different. What is the media? To put it bluntly, it is the substance between the two plates of the capacitor. Most of the polar capacitors use electrolyte as the dielectric material, usually the same volume of the capacitor has a large capacity. In addition, polarized capacitors manufactured by different electrolyte materials and processes have different capacities with the same volume. There is also a close relationship between pressure resistance and the use of dielectric materials. There are also many non-polar capacitor dielectric materials, most of which use metal oxide film, polyester and so on. Because the reversible or irreversible performance of the medium determines the use environment of polar and non-polar capacitors.
The performance of the two is different, performance is the requirement of use, and maximum demand is the requirement of use. If a metal oxide film capacitor is used for filtering in the power supply part of the TV, and the capacitor capacity and withstand voltage required for filtering must be achieved. I am afraid that only one power supply can be installed in the case. Therefore, only polar capacitors can be used as filters, and polar capacitors are irreversible. That is to say, the positive pole must be connected to the high potential end, and the negative pole must be connected to the low potential end. Generally, electrolytic capacitors are above 1 microfarad for coupling, decoupling, power filtering, etc. Most non-polar capacitors are below 1 microfarad and participate in resonance, coupling, frequency selection, and current limiting. There are also large-capacity and high withstand voltage, which are mostly used for reactive power compensation of electric power, phase shifting of motors, and frequency conversion power shifting.
The capacity of the two is different, and the capacity of the capacitor medium of the volume is different, so I won't repeat them here.
The two structures are different. In principle, without considering the tip discharge, any shape of capacitor can be used in the environment. The commonly used electrolytic capacitors (with polarized capacitors) are round, and square ones are rarely used. The shapes of non-polar capacitors vary. Like tube type, deformed rectangle, sheet type, square type, round type, combined square type and round type, etc., depending on where they are used. Of course, there are also intangibles. The intangibles here refer to distributed capacitance. Distributed capacitance must not be ignored in high frequency and intermediate frequency devices. The function is the same. The main difference is in the capacity, affected by the material structure, generally the capacity of non-polar capacitors is relatively small, generally below 10uF, while the capacity of polar capacitors is generally larger. For example, when performing power filtering, you have to use large-capacity polar capacitors.