Film capacitor types and applications

Chip ceramic capacitor

Tantalum capacitor

Capacitor Type Capacitors vary depending on the medium. There are many types of capacitors, such as electrolyte capacitors, paper capacitors, film capacitors, ceramic capacitors, mica capacitors, and air capacitors. However, the most frequently used in audio equipment is electrolytic capacitors and film capacitors. Electrolytic capacitors are mostly used where large capacitance is required, such as filter capacitors in the main power supply, in addition to filtering, and also for storing electrical energy. Thin film capacitors are widely used in the intersection of analog signals, bypass of power supply noise (anti-intersection) and so on. The film capacitor is a capacitor in which a metal foil is used as an electrode and a plastic film such as polyethylene, polypropylene, polystyrene or polycarbonate is stacked from both ends and wound into a cylindrical structure. According to the type of plastic film, it is called polyethyl capacitor (also known as Mylar capacitor), polypropylene capacitor (also known as PP capacitor), polystyrene capacitor (also known as PS capacitor) and polycarbonate capacitor.

Film Capacitor Advantages Film capacitors are excellent capacitors because of their excellent characteristics. Its main equivalence is as follows: no polarity, high insulation resistance, excellent frequency characteristics (wide frequency response), and low dielectric loss. Based on the above advantages, the film capacitor is used in a large amount on an analog circuit. In particular, in the part where the signal is connected, it is necessary to use a capacitor having a good frequency characteristic and a very low dielectric loss to ensure that the signal is transmitted without excessive distortion. Among all the plastic film capacitors, the characteristics of polypropylene (PP) capacitors and polystyrene (PS) capacitors are the most significant. Of course, the prices of these two capacitors are also relatively high. However, in recent years, in order to improve the quality of sound equipment, the materials used have become more and more advanced, and the price is not the most important consideration. Therefore, in recent years, the frequency and quantity of PP capacitors and PS capacitors used in audio equipment are also increasing. The higher the height. Readers can often see a certain brand of equipment, claiming how many brand-name PP capacitors or PS capacitors are used as endorsements in sound quality. The reason is here.

Film Capacitor Method A film capacitor is usually produced by winding a metal foil such as aluminum as an electrode and a plastic film. However, another film capacitor has a manufacturing method called Metallized Film, which is formed by vacuum-depositing a thin layer of metal on the plastic film as an electrode. In this way, the thickness of the electrode foil can be omitted and the volume per unit capacity of the capacitor can be reduced, so that the film capacitor can be easily formed into a small-sized, large-capacity capacitor. For example, the common MKP capacitor is the name of Metailized Polypropylene Film Capacitor, and MKT is the name of Metailized Polyester.

The film used for the metallized film capacitor metallized film capacitor is polyethylene, polypropylene, polycarbonate, etc., and has a laminate type in addition to the wound type. Metalized film This type of capacitor has a so-called Self Healing Action, which assumes that the tiny part of the electrode is short-circuited due to the fragile electrical boundary, causing the electrode metal around the short-circuited portion. Due to the electrostatic energy or short-circuit current of the capacitor at that time, a larger area of ​​melting and evaporation is initiated to restore the insulation, so that the capacitor returns to the capacitor again.

Acoustic capacitors are the earliest and most well-known film capacitors used in audio equipment. They are the first WIMA containers known as the red elixir or the German elixir. In the early years when there were no so-called tonic parts in Taiwan, WIMA was the only high-end item on the market. (Circuit Map Home http://) Although the advancement of materials and technology and the market demand, the high-end film capacitors of various brands have been dazzling, but WIMA should still be the most well-known brand. . The most famous capacitor of WIMA is the PP capacitor of the number MKP-10.

Common brands of acoustic capacitors

After WIMA, audio products are also used a lot, very historical, is the German brand ERO capacitors. The most common ERO capacitors are green, and some are blue. When they are assembled on the board at the same time as WIMA, they are interesting. ERO is the brand of film capacitors, and ROE is another brand of advanced electrolyte capacitors, the same as the English alphabet, but the order is different, the reader can not be confused. The same as the German brand, but the Siemens products are not used too much in the audio products, this brand of soap electrolyte capacitors and film capacitors are used by the German HI-END factory MBL, and the performance is excellent, so the strength is not small watch for.

Philips is a large enterprise group, and its products are manufactured in countless varieties. From the most popular household appliances to the most advanced space technology, the production of capacitors will not be missed. Its capacitors, the appearance of a faint water blue, have recently been found in audio equipment.

Rifa is a high-end capacitor of the Swedish brand. The common PP capacitor is blue. The specifications and sound performance are excellent, but the price is also very expensive. Therefore, few audio manufacturers use it, but I only need to point out three uses. You can probably understand the strength of this brand's audio factory. What about those three? Gryphon of Denmark, Mark Leivenson of the United States and Cello.

Wonder capacitors and Relcap capacitors are high-level capacitors that have been used for a while in the past few years. The use of Wonder capacitors is best known for Counterpoint machines. It is also used by Audio Research. The appearance is white cylinder type and the sealant is green. Relcap is best known for its use in Audio Research, with a pale yellow elliptical column.

France's Solen capacitors have also become very popular in recent years. Its appearance is cylindrical, black skin, and both ends are sealed in brick red and gray. It is by far the only manufacturer that produces large-capacity MKP capacitors (up to 200F), so Solen capacitors are used in a large number of high-end loudspeakers, known as Dynaudio loudspeakers in Denmark, USA Infinity speakers (including the IRS-V mid-high column), France's JM Lab speakers (the flag of ALCOR and UTOPIA more carefully on the speaker back panel, with transparent acrylic show special customized super large Solen capacitors to show the extraordinary use of materials.) In addition, many of the well-known manufacturers of crystal or tube machine circuits are used a lot.

Historically, MIT capacitors are the youngest advanced capacitors. They may not be available for three years, but since they were launched, they can be described as "sensational martial arts and alarming Wanjiao". It was once the whole HI-END. The topic of the audio circle. The reason is that its structure is special, MIT capacitor is a composite capacitor (Multi cap), which means that a capacitor is actually internally composed of multiple capacitors in parallel. What are the advantages of doing this? Once again, the equivalent series resistance and the equivalent series inductance value inside the capacitor can be reduced, so that the MIT capacitor is closer to the ideal capacitor, so all the technical specifications are also excellent! Of course, this is a price to pay. The price of MIT capacitors is expensive enough to discourage manufacturers or individuals who want to use it. This is also its second most compelling place. In addition, its volume is also relatively large in terms of the same capacity, and the convenience of application is limited in circuits that pay attention to the mounting density of parts. Its appearance is white oval column type, the lead wire is very thick, the sealant is black, and it has two types of metal foil and metallized film.

The structure is the same as the paper dielectric, and the medium is polyester or polystyrene. Polyester film capacitor, high dielectric constant, small size, large capacity, good stability, suitable for bypass capacitors.

Polystyrene film capacitors, low dielectric loss, high insulation resistance, but high temperature coefficient, can be used in high frequency circuits.