Polar capacitance refers to a type of electrolytic capacitor, which is formed by the anode of the aluminum foil and the cathode electrolyte are formed by the two electrodes on the anode foil produced by a layer of aluminum oxide film as a dielectric capacitor .As a result of this Structure, so that it has a polarity, when the capacitor is connected directly, the aluminum oxide film will be due to the electrochemical reaction and stability, when the reverse connection, the aluminum oxide layer will be thinner, so that the capacitor is easily damaged by breakdown. So the electrolytic capacitor Circuit must pay attention to the polarity of the ordinary capacitor is non-polar, you can also put the two electrolytic capacitor anode or cathode relative to form a series of non-polar electrolytic capacitor.

1, the same principle. (1) are stored charge and release the charge; (2) the voltage on the plate (where the charge accumulated electromotive force called voltage) can not be abrupt change. (3) The difference is that different media, different performance, different capacity, different structures lead to the use of different environments and purposes. Conversely speaking, according to the needs of production practice, people experimentally manufactured a variety of functional capacitors to meet the normal operation of various appliances and the operation of new equipment. With the development of science and technology and the discovery of new materials, higher quality and diversified capacitors will continue to emerge. 2, different media. What is the medium? To put it bluntly is the material between the two plates of the capacitor. Most of the polar capacitors are made of electrolyte dielectric material, usually the same volume of capacitance has a large capacity of the capacitor. In addition, different electrolyte materials and processes to create a polar capacitor capacity with the same volume will be different. Then there is pressure and the use of media materials are also closely related. Non-polar capacitor dielectric material is also many, most of the metal oxide film, polyester and so on. Due to the reversible or irreversible nature of the media determines the polar, non-polar capacitance of the use of the environment. The company is located in:

3, different performance. Performance is the use of the requirements, the demand is to use the maximum demand. If the power supply part of the TV with metal oxide film capacitors filter, but also to achieve the filter capacitor capacity and voltage. I am afraid that the chassis can only contain a power supply. So as a filter can only use a polar capacitor, a polar capacitor is irreversible. In other words, the positive electrode must be connected to the high potential end and the negative electrode must be connected to the low potential end. Electrolytic capacitors in general more than 1 micro-Faraday, so coupling, back coupling, power filter and so on. Most non-polar capacitors below 1 micro-farad, involved in resonance, coupling, frequency selection, current limiting, and so on. Of course, there are large-capacity high voltage, and more used in reactive power compensation, motor phase-shifting, frequency conversion power phase applications. There are many types of non-polar capacitors, not repeat them. The company is located in:

4, different capacity. Have already talked about the same volume of capacitor media with different capacities, not repeat them. 5, different structures. In principle, regardless of the state of the tip discharge, what kind of capacitance is required for the environment to be used. The commonly used electrolytic capacitor (with polar capacitor) is round, very few square. Uncomplexed shape of the capacitor unpredictable. Like tube type, rectangular deformation, slice, square, round, combination of square and round, etc., to see where used. Of course, there are invisible, where invisible is the distribution of capacitance. For distributed capacitance in high-frequency and IF devices can not be ignored. The company is located in:

Functionally the same. The main difference is in the capacity, by the material structure, the general capacity of non-polar capacitors are relatively small, generally below 10uF, while the capacity of the polar capacitor is generally larger. For example, in the power filter, you have to use a large capacity of the polar capacitor. The company is located in:

A basic principle of circuit design is to require designers to fully understand and grasp the reality of the components, components used as much as possible standard parts, common parts, it is best on the market the most common type (component versatility, Procurement more easily, the greater the supplier output, the lower the procurement costs). For the components used in the drawings, if only the materials can be obtained by customization, the cost is certainly not low. If you can not get custom, then this design is equivalent to waste paper. The company is located in:

PS: What you are talking about is power decoupling capacitor, large capacitor suitable for filtering low frequency signal, small capacitor filtering high frequency signal. The company is located in:

However, decoupling is only a role of the capacitor, the capacitor has other functions, different types of capacitor characteristics, usage is very different, the schematic is only a symbol of the capacitor only, and more behind the trick yet. This aspect is closely related to experience and can not be achieved quickly. It can only be accumulated slowly through practice.