A capacitor is an electronic device designed to store electric charge and field energy. There are many types of capacitors and their designs. In this article, we will talk about ceramic capacitors of the KM type. Capacitors of this type are used in industrial equipment, in the manufacture of high-precision measuring instruments, radio transmitters, as well as in the military industry.
KM ceramic capacitors are highly stable, they are designed to operate in pulsed modes, as well as in AC and DC circuits. They are characterized by high adhesion of plates to ceramics, as well as slow aging, which ensures a low coefficient of capacitive temperature instability. KM capacitors, with rather small dimensions, have a high capacitance (reaching 2.2 microfarads). However, the change in capacitance value in the operating temperature range for KM ceramic capacitors ranges from 10 to 90%.
KM group H capacitors are most often used inas transitional, blocking, etc. Modern KM ceramic capacitors are made by pressing under pressure into a monolithic block of thin metallized ceramic plates. Due to the high strength of the mentioned material, it is possible to use very thin workpieces, as a result, the capacitance of the obtained capacitors, proportional to unit volume, increases sharply.
KM type capacitors also differ from other capacitors in their high price. The reason is that they use the following precious metals (and their mixtures) as dielectric plates: Ag, Pl, Pd. In most cases, palladium is used, and this is precisely what determines their value. In this regard, not only new products are in great demand, but also used ones and even those that have become unusable. Precious metals are contained in KM3-6 type capacitors. They are divided into two types: palladium (KM H90) and platinum (KM H30). There is another subspecies of KM capacitors of the H30 group - this is KM5 D, which differ from H30 in that there is much less platinum in them. The content of precious metals in KM H90 is 46.5 g of palladium and 2.5 g of platinum per kilogram of capacitors. And in capacitors of the KM H30 type, it is 50 g of platinum per kilogram of capacitors.
KM D group capacitors (green) contain 40 gr. platinum, that is, 20% less than in the capacitors of the H30 group (green). Capacitors of the KM type of the H90 group, having the letter V in their marking,contain 10% more precious metals than capacitors of the H90 group. In theory, such capacitors should be more expensive than other ceramic capacitors of the H90 green group. And smaller capacitors should be cheaper. In practice, all KM capacitors of the H90 green group cost the same. The cost of KM capacitors directly depends on the price of precious metals, as well as on the cost of refining costs. The most common KM ceramic capacitors (the photo shows the appearance of KM type capacitors) are KM capacitors of the H90 group of green and orange colors.
