Radioelements from old equipment: capacitors. Ceramic capacitors km Where to find capacitors

They are polar and non-polar. Their differences are that some are used in DC voltage circuits, while others are used in AC circuits. It is possible to use permanent capacitors in alternating voltage circuits when they are connected in series with the same poles, but they do not show the best parameters.

Non-polar capacitors

Non-polar, just like resistors, are constant, variable and trimming.

Trimmers capacitors are used to tune resonant circuits in transmitting and receiving equipment.

Rice. 1. PDA capacitors

PDA type. They consist of silver-plated plates and a ceramic insulator. They have a capacity of several tens of picofarads. It can be found in any receivers, radios and television modulators. Trimmer capacitors are also designated by the letters KT. Then follows a number indicating the type of dielectric:

1 - vacuum; 2 - air; 3 - gas-filled; 4 - solid dielectric; 5 - liquid dielectric. For example, the designation KP2 means a variable capacitor with an air dielectric, and the designation KT4 means a tuning capacitor with a solid dielectric.

Rice. 2 Modern trimming chip capacitors

To tune radio receivers to the desired frequency, use variable capacitors(KPE)

Rice. 3 Capacitors KPE

They can only be found in transmitting and receiving equipment

1- KPE with an air dielectric, can be found in any radio receiver of the 60s-80s.
2 - variable capacitor for VHF units with vernier
3 - variable capacitor, used in receiving technology of the 90s to this day, can be found in any music center, tape recorder, cassette player with a receiver. Mostly made in China.

There are a great many types of permanent capacitors; within the framework of this article it is impossible to describe all their diversity; I will only describe those that are most often found in household equipment.

Rice. 4 Capacitor KSO

KSO capacitors - Pressed mica capacitor. Dielectric - mica, plates - aluminum coating. Filled in a brown compound housing. They are found in equipment from the 30s to the 70s, the capacity does not exceed several tens of nanofarads, and is indicated on the housing in picofarads, nanofarads and microfarads. Thanks to the use of mica as a dielectric, these capacitors are capable of operating at high frequencies because they have low losses and have a high leakage resistance of about 10^10 Ohms.

Rice. 5 Capacitors KTK

KTK capacitors - Tubular ceramic capacitor. A ceramic tube and silver plates are used as a dielectric. Widely used in oscillatory circuits of lamp equipment from the 40s to the early eighties. The color of the capacitor indicates TKE (temperature coefficient of change of capacitance). Next to the container, as a rule, the TKE group is written, which has an alphabetic or numerical designation (Table 1.) As can be seen from the table, the most heat-stable ones are blue and gray. In general, this type is very good for HF equipment.

Table 1. TKE marking of ceramic capacitors

When setting up receivers, you often have to select capacitors for the local dyne and input circuits. If the receiver uses KTK capacitors, then selecting the capacitance of the capacitors in these circuits can be simplified. To do this, several turns of PEL 0.3 wire are wound tightly onto the capacitor body next to the terminal and one of the ends of this spiral is soldered to the terminal of the capacitors. By spreading and shifting the turns of the spiral, you can adjust the capacitance of the capacitor within small limits. It may happen that by connecting the end of the spiral to one of the terminals of the capacitor, it is not possible to achieve a change in capacitance. In this case, the spiral should be soldered to another terminal.

Rice. 6 Ceramic capacitors. Soviet ones at the top, imported ones at the bottom.

Ceramic capacitors are usually called “red flag” capacitors, sometimes called “clay” capacitors. These capacitors are widely used in high frequency circuits. Typically, these capacitors are not quoted and are rarely used by hobbyists, since capacitors of the same type can be made of different ceramics and have different characteristics. Ceramic capacitors gain in size but lose in thermal stability and linearity. Capacity and TKE are indicated on the body (Table 2.)

table 2

Just look at the permissible change in capacitance for capacitors with TKE N90, the capacitance can change almost twice! For many purposes this is not acceptable, but still you should not reject this type; with a small temperature difference and not strict requirements, they can be used. By using parallel connection of capacitors with different signs of TKE, it is possible to obtain a fairly high stability of the resulting capacitance. You can find them in any equipment; the Chinese are especially fond of them in their crafts.

They have a capacity designation on the body in picofarads or nanofarads; imported ones are marked with a numerical code. The first two digits indicate the capacitance value in picofarads (pF), the last two digits indicate the number of zeros. When the capacitor has a capacitance of less than 10 pF, the last digit may be "9". For capacitances less than 1.0 pF, the first digit is “0”. The letter R is used as a decimal point. For example, code 010 is 1.0 pF, code 0R5 is 0.5 pF. Several examples are collected in the table:

Alphanumeric marking:
22p-22 picofarads
2n2- 2.2 nanofarads
n10 - 100 picofarads

I would like to especially note ceramic capacitors of the KM type, they are used in industrial equipment and military devices, they have high stability, they are very difficult to find because they contain rare earth metals, and if you find a board where this type of capacitor is used, then in 70% of cases they were cut out before you).

In the last decade, radio components for surface mounting have very often begun to be used; here are the main standard sizes of housings for ceramic chip capacitors

MBM capacitors are a metal-paper capacitor (Fig. 6), usually used in tube sound amplification equipment. Now highly prized by some audiophiles. This type also includes military-grade K42U-2 capacitors, but they can sometimes be found in household equipment.

Rice. 7 Capacitor MBM and K42U-2

It should be noted separately that such types of capacitors as MBGO and MBGCh (Fig. 8), are often used by amateurs as starting capacitors to start electric motors. As an example, my engine reserve is 7 kW (Fig. 9.). Designed for high voltage from 160 to 1000V, which gives them many different applications in everyday life and industry. It should be remembered that for use in a home network, you need to take capacitors with an operating voltage of at least 350V. You can find such capacitors in old household washing machines, various devices with electric motors and in industrial installations. They are often used as filters for acoustic systems, having good parameters for this.

Rice. 8. MBGO, MBGCH

Rice. 9

In addition to the designation indicating design features (KSO - compressed mica capacitor, KTK - ceramic tubular capacitor, etc.), there is a designation system for constant-capacity capacitors, consisting of a number of elements: in the first place is the letter K, in the second place is a two-digit number, the first digit of which characterizes the type of dielectric, and the second - the features of the dielectric or operation, then the serial number of the development is put through a hyphen.

For example, the designation K73-17 means a polyethylene-terephthalate film capacitor with a development serial number of 17.

Rice. 10. Different types of capacitors

Rice. 11. Capacitor type K73-15

Main types of capacitors, imported analogues in parentheses.

K10 - Ceramic, low voltage (Upa6<1600B)
K50 - Electrolytic, foil, Aluminum
K15 - Ceramic, high voltage (Upa6>1600V)
K51 - Electrolytic, foil, tantalum, niobium, etc.
K20 - Quartz
K52 - Electrolytic, volumetric porous
K21 -Glass
K53 - Oxide semiconductor
K22 - Glass-ceramic
K54 - Oxide-metallic
K23 - Glass enamel
K60- With air dielectric
K31-Mica low power (Mica)
K61 - Vacuum
K32 - Mica high power
K71 - Film polystyrene (KS or FKS)
K40 - Paper low-voltage (Irab<2 kB) с фольговыми обкладками
K72 -Film fluoroplastic (TFT)
K73 - Film polyethylene tereph-talate (KT, TFM, TFF or FKT)
K41 - Paper high-voltage (irab>2 kB) with foil coverings
K75 -Film combined
K76 – Lacquer film (MKL)
K42 - Paper with metallized covers (MP)
K77 - Film, Polycarbonate (KC, MKC or FKC)
K78 – Film polypropylene (KP, MKP or FKP)

Capacitors with a film dielectric are popularly called mica; the various dielectrics used give good TKE indicators. As plates in film capacitors, either aluminum foil or thin layers of aluminum or zinc deposited on a dielectric film are used. They have fairly stable parameters and are used for any purpose (not for all types). They are found everywhere in household equipment. The housing of such capacitors can be either metal or plastic and have a cylindrical or rectangular shape (Fig. 10.) Imported mica capacitors (Fig. 12)

Rice. 12. Imported mica capacitors

On capacitors, the nominal deviation from the capacitance is indicated, which can be shown as a percentage or have a letter code. Basically, in household equipment, capacitors with tolerances H, M, J, K are widely used. The letter indicating the tolerance is indicated after the value of the nominal capacitance of the capacitor, like 22nK, 220nM, 470nJ.

Table for deciphering the conditional letter code of the permissible deviation of capacitor capacitance. Tolerance in %

The value of the permissible operating voltage of the capacitor is important; it is indicated after the rated capacity and tolerance. It is designated in volts with the letter B (old marking) and V (new marking). For example, like this: 250V, 400V, 1600V, 200V. In some cases, the V is omitted.

Sometimes Latin letter coding is used. To decipher, you should use the letter coding table for the operating voltage of capacitors.

Fans of Nikola Tesla have a frequent need for high-voltage capacitors, here are some that can be found, mainly in televisions in horizontal scanning units.

Rice. 13. High voltage capacitors

Polar capacitors

Polar capacitors include all electrolytic ones, which are:

Aluminum electrolytic capacitors have high capacity, low cost and availability. Such capacitors are widely used in radio instrument making, but have a significant drawback. Over time, the electrolyte inside the capacitor dries out and they lose capacity. Along with the capacitance, the equivalent series resistance increases and such capacitors no longer cope with the assigned tasks. This usually causes malfunctions in many household appliances. Using used capacitors is not advisable, but still, if you want to use them, you need to carefully measure the capacitance and esr, so that you don’t have to look for the reason for the device’s inoperability. I don’t see any point in listing the types of aluminum capacitors, since there are no special differences in them, except for geometric parameters. Capacitors can be radial (with leads from one end of the cylinder) and axial (with leads from opposite ends), there are capacitors with one lead, the second one is a housing with a threaded tip (it is also a fastener), such capacitors can be found in old tube radio-television equipment. It is also worth noting that on computer motherboards and in switching power supplies there are often capacitors with low equivalent resistance, the so-called LOW ESR, so they have improved parameters and are replaced only with similar ones, otherwise there will be an explosion when first turned on.

Rice. 14. Electrolytic capacitors. Bottom - for surface mounting.

Tantalum capacitors are better than aluminum capacitors due to the use of more expensive technology. They use a dry electrolyte, so they are not prone to “drying out” of aluminum capacitors. In addition, tantalum capacitors have lower active resistance at high frequencies (100 kHz), which is important when used in switching power supplies. The disadvantage of tantalum capacitors is the relatively large decrease in capacitance with increasing frequency and increased sensitivity to polarity reversal and overloads. Unfortunately, this type of capacitor is characterized by low capacitance values ​​(usually no more than 100 µF). High sensitivity to voltage forces developers to increase the voltage margin by two or more times.

Rice. 14. Tantalum capacitors. The first three are domestic, the penultimate one is imported, the last one is imported for surface mounting.

Main dimensions of tantalum chip capacitors:

One of the types of capacitors (in fact, these are semiconductors and have little in common with ordinary capacitors, but it still makes sense to mention them) include varicaps. This is a special type of diode capacitor that changes its capacitance depending on the applied voltage. They are used as elements with electrically controlled capacitance in circuits for tuning the frequency of an oscillatory circuit, dividing and multiplying frequencies, frequency modulation, controlled phase shifters, etc.

Rice. 15 Varicaps kv106b, kv102

Also very interesting are “supercapacitors” or ionistors. Although small in size, they have enormous capacity and are often used to power memory chips, and sometimes they replace electrochemical batteries. Ionistors can also work in a buffer with batteries in order to protect them from sudden surges in load current: at low load current, the battery recharges the supercapacitor, and if the current increases sharply, the ionistor will release the stored energy, thereby reducing the load on the battery. With this use case, it is placed either directly next to the battery or inside its housing. They can be found in laptops as a battery for CMOS.

The disadvantages include:
Energy density is lower than that of batteries (5-12 Wh/kg at 200 Wh/kg for lithium-ion batteries).
The voltage depends on the state of charge.
Possibility of internal contacts burning out during a short circuit.
High internal resistance compared to traditional capacitors (10...100 Ohms for a 1 F × 5.5 V ionistor).
Significantly greater self-discharge compared to batteries: about 1 µA for a 2 F × 2.5 V ionistor.

Rice. 16. Ionistors

You know that iron must be forged while someone else needs it, even without a blacksmith
(Why do we need a blacksmith? We don’t need a blacksmith). And the fact that a spoon is dear to dinner is also not true.
the last one. This is what I want to tell you about an expensive spoon made of iron, or rather rare iron,
especially since lunch has already been served.

The metal for which this review is geared is palladium. Palladium is included in platinum
group. This noble metal is widely used in various industries. All
We are not interested in the range of applications. Only two areas are of decisive importance - mechanical engineering
and electronic. And while in the first the demand for palladium is growing, in the second it has almost stopped. And I
I think, although this is not relevant, that not the least role in the fall in demand for this metal among
radio industry enterprises played a role in reducing spending on military needs of the state.
But before we were richer and could afford the luxury of riveting parts with specific
content of rare and therefore expensive metals. Of course, not for general use.
The slogan was strictly observed: All the best goes to children! And the children, we know who they are - a horse in a coat and shoulder straps.
Until they play enough with their toys, we won’t get any.

But some things also fell to civilian radio destroyers, and not only from thieves, modestly called “nonsuns,” but also in various sets
the number is so much for young soldering detector receivers.
Palladium is very refractory, which allows components made on its basis
It is normal and smooth to work in the epicenter of a nuclear explosion. This is of course a joke, but still.
Contacts of switches and trimmers made using palladium,
withstand more aggressive environments and are less susceptible to oxidation. Capacitors,
containing palladium, operate in a very wide temperature range without changing their electrical
parameters aka capacitance, and have low leakage currents, which again is for a walkie-talkie on an armored train,
which is either fire or water - one piece of crap, just a godsend.

Since you probably still don’t understand why I’m telling you all this, I’ll say it as a starter
- for a kilogram of such condensers without leads (legs), they give a piece of bucks (A THOUSAND US DOLLARS). Behind
volume that fits in less than fifteen matchboxes, such money! Agree, there's a reason
worthy of sparking a gold rush. Money is around you, it literally lies under your feet, you just need to know what, where and where it comes from.
The reserves of palladium accumulated in the form of radio components by our radio amators are so large that the method
mining this metal, known as “Extracting cheese from dumplings,” more than pays for itself. One hundred
grams of pure product, on the world market, costs about three thousand bucks, they will give you a hundred,
however, for one hundred grams of capacitors containing no more than 20 percent palladium. Do you feel
how the chain of bought-processed-exported-sold is overgrown with cabbage. But getting into the thick of it
actions have no reason for us. It is very dangerous for health IMHO, but we need to take care of our health. You will
All you need is a guy from the nearest radio market who will gladly change the price of your parts
for evergreen and therefore always relevant money.

To tell the truth, radio components containing precious metals have always been bought. But the price of palladium
has more than doubled in the last year alone and has become a third more expensive even than platinum, which
has always been a leader in terms of cost. Predict how long this situation will last
It’s hard, and I’m not an expert on this issue.
In general, the growth of something can always be simply explained. The monopolist twists his arms.
Palladium is no exception. The monopolist in this case is Russia, which sells
The world market accounts for 70 percent of this metal. Monopolist No. 1 - President of Russia, monopolist No. 2 - RAO
"Norilsk Nickel". The first gives a sales quota and sets the duty, and the second actually
digs up and packs in beautiful boxes. Now let's deal with those who are creating the hype,
jostles in line and inflates prices.
Almost all palladium is bought by automobile factories in Europe, the USA and Japan. Introduction
Since January 2000, new emission standards in the USA and Europe have forced manufacturers to
1998-1999 significantly increase the production of automobile engines equipped with catalysts.
As a result, the demand for palladium, which is used to produce automobiles,
catalysts, has recently increased significantly.
It is believed that the European Union will again tighten legislation in this area in
2004-2005, by which time the US government will probably also revise the maximum
permissible standards for the content of environmentally harmful substances in automobile exhausts. And although
industry is actively trying to develop a new model of catalyst, where the use
palladium would be more effective by improving technologies for its application or use
other platinum group metals, according to experts, further growth in demand for palladium
inevitable. In Japan, new emission restrictions will be introduced a little later and in several steps
- until the end of 2002. But Japanese car manufacturers are already forced to equip
export models with palladium catalysts. Therefore, their third of palladium is regularly shipped
and they.

By and large, we, the global problems of the automotive industry, don’t give a damn, we don’t
obliged. According to the ancient Russian tradition, delivery deadlines are not observed at all. The enemies
The technical process is scheduled minute by minute, years in advance. Any failure causes untold losses. In order to
For self-education, I recommend reading “Wheels” by A. Haley, about the work of Ford factories. The only one,
Probably, who gives a damn about all this fuss - “Zaporozhets”. This foreign car's exhaust is OK.

Now imagine - the whole of January is continuous holidays, then preparations for February 23rd,
and March 8 is just around the corner. So it turns out that no one is going anywhere before April 1st.
For obvious reasons, for three, four, five months, foreign automobile factories
will not stop. So they have to raise prices at the end of the year, creating
strategic reserves, knowing our unpredictability and optionality. And since the demand for
palladium grows every new year, then with the beginning of the sales season it does not fall. That we are not
may not please you. That's it, theory is over, practice is on. Although there was a temptation to split the review into two parts.
Long texts on the screen are difficult to read. But, crunch the wrapper and hide the candy for a few more
days I considered it dishonest. So do a couple of squats and let's continue.

If you are not a professional radio destroyer, use my picture. I did
photo of the most delicious details. We need to know by sight those whom we will take. You do not have to
make a mistake.

WARNING! They explained to you that stealing is wrong in kindergarten. In your own
At age it should already be clear that this is fraught with sad consequences. The best thing
exchange the things you need from the natives for mirrors and trinkets, for “fire” water, in
Eventually. So, the first number is ceramic capacitors KM-3,4,5,6. Maximum rating
- about a buck per kilogram without legs. The capacitor type is usually marked
the corresponding number. KM-4.5 are rectangles or squares of different sizes
and various shades of green. WITH
military show-off. KM-6 are made, as a rule, in the form
pads of brownish-red tones. There are open-frame versions of capacitors. In such
In this case, they look like small, ashen-colored rectangles.
During the Soviet era, large computers with significant content were produced
KM-ok. This decommissioned car is just a Jack the Ripper dream. Unfortunately, such technology is cunning
the boys had already become afraid by the mid-nineties. But then the hunt was for gold connectors, and the boards
with palladium-containing condensers now rising in price, they went into the trash. Maybe it's time to dig up
dead people?

I remember somewhere in X there was a circuit diagram for a metal detector, because all radio factories recycled
their illiquid assets using a bulldozer. There was a lot of this goodness in the first Soviet personal
computers. In "BK" from "Electronics", in Kyiv "Poiski", in Minsk ES1840...43. Suddenly someone
waiting for an upgrade? And it will be good for him, and you will get money.
Instrumentation and control equipment (instruments) are considered another repository of treasures.
Generators, voltmeters, oscilloscopes. You understand that their readings should not depend on the weather
outside the window and therefore they used the “correct” parts. To the most “precious” devices
relate:

Oscilloscope: S-114, 116, 120, 121, 125; S1-9-9, S9-11, S9-27,28.
Analyzer: SCh-60, SCh-74, SCh-82.
Meter: E7-14.15; R2-73, 85, 86, 102; RF-37; SK8-4B.
Generator: ГЧ-151, 164, 165,176; G3-122, 123; RF6-01.
Frequency meter: SCh8-68, 68/1; SCH8-74.
Voltmeter: V1-28; B3-63; B7-40, 46.

With regard to devices, the approach is twofold, depending on the level of integrity
the ripper. The first one is used by scumbags. All the tasty details are bitten out and a
imitation of the operation of the device, burning lights, humming wires, etc. In general, it’s a complete phony, no
has nothing to do with measurements. This is the g...
sold to a gullible buyer for considerable
money. I would kill such rationalizers. The second approach is more complex, but quite acceptable
- all expensive radio components are replaced with inexpensive analogues. As a result, the output
we get a fully functional product, plus a bag of treasures.

Let's go through capacitors again, but this time containing another component - tantalum.
Prices for it are much lower, but also impressive, especially since capacitors based on them
The people have even more reserves than palladium. Look at the picture. THIS, THIS-1,2 large green washers
or gray colors. They are accepted individually, for about two bucks apiece. The same, only series
K52-2 costs 30 cents cheaper. For small execution they give 25-30 cents. The biggest
K52-1 capacitors are bought for 80 cents, and in addition to everything else, they also have a silver case.
K53-1, 7, 18, 20 charge 20 cents each, but this is for the largest sizes. The smaller the dimensions, the
cheaper.

Above, I already mentioned super-reliable palladium contacts. The picture shows
trimming resistor with such a contact - PP3-43. It costs one and a half dollars. They take everything
PP3-40...47 from '67 to '82 inclusive. They do not refuse SP5, but those produced before 92.
Here is another list: PPBP, P-74, RPP, PTP-1,2,5, PPMP, PPMP-I, PPMP-M, PPMP-IM, PPMFM.
In civilian reference books you will not find information on all these radio components, complete data
are only available in data sheets, so I provide only short lists. The next ones went
switches: BKNB, PG-2, PG-5, PG-7, PG-43, P1T3-1, PR-2, PR-5, PR-10, PP-6, PM2-1, MP12,
P1M10, P1M9-1, PKN-2,4,19, P2KN, PT8.7-12, PT11-1, PT9,13-1, P2KnT 3V, 4V, 4T, A18.
The price and demand correspond to my local radio market. Considering the general trend for
once indestructible and powerful, one might say - in the adjacent territory there is a demand for such
iron is and will always be. Obviously, this business can be done ALMOST legally, because...
activities for collecting non-ferrous metals are licensed. Activities without a license are
violation under Art. 171 of the Criminal Code of the Russian Federation, with volumes exceeding 200 mrot. List of licensed
collection points for non-ferrous metals can be found in the relevant department of the local administration.

May the wire cutters be with you at the right moment!

A capacitor is a device that is capable of storing and releasing electrical energy. Capacitors are present wherever there is electrical current. They occupy from 15% to 20% of the list of components in almost any electronic equipment.

A little history

The year of invention of the capacitor is considered to be 1745. This invention belongs to German and Dutch physicists: Ewald Jurgen von Kleist and Peter van Musschenbroeck. This first prototype of an electric capacitor was called the “Leyden jar” (after the city of Leiden, where this design was assembled).

Main characteristics

KM capacitors are ceramic monolithic capacitors in cased and uncased versions. They belong to the subclass of constant capacitors. According to the classification, these are low-voltage capacitors with voltages up to 1600 V. The capacitance range is from 16 pF to 2.2 μF. Is it a lot or a little? For comparison, let's say that the Earth's capacitance is about 710 microfarads.

The KM group of low-voltage capacitors is divided into low-frequency and high-frequency. According to their purpose, they are divided into three groups: 1, 2 and 3.

— group 1 is used when high capacity stability and low losses are essential;
— group 2 — when Not What is significant is what is characteristic of group 1;
- group 3 - like the second group, but is intended for operation in low-frequency circuits.

There are more than ten basic electrical parameters for each capacitor and more than 25 performance characteristics. We emphasize that these are only the main ones; the full list is close to 60.
Let's look at some of them.

Nominal capacity. This value is standardized and selected from a certain series - E3, E6, E12, E24, E48, E96, E192. For each decimal interval, the numbers after E indicate the number of nominal values. So, for example, for E6 we have a number of nominal capacity values: 1.0 1.5 2.2 3.3 4.7 6.8 (for each decimal interval).

For nominal values ​​there is a limit of permissible deviations, which is expressed as a percentage. For example: ±0.1%, ±0.25%, ... ±30%, (-10+30)%, (-20+50)%.

Rated voltage. This is the voltage at which the capacitor can operate under certain conditions and maintain its parameters within acceptable limits. For KM capacitors, depending on the modification, the range of values ​​lies from 25V to 250V.

Temperature coefficient of capacity (TKE). It is used for capacitors with a linear dependence of capacitance on temperature.

TKE value: using this parameter, you can determine how much the capacitance of the capacitor will change if the ambient temperature changes by one degree in a given temperature range (both Celsius and Kelvin scales are used). A number of TKE KM capacitors: P33, MPO, M47, M75, M750, M1500, N30, N50, N90.

Modifications of KM capacitors

The following modifications of capacitors were made: KM-3, KM-4, KM-5, KM-6.

KM-4, KM-5, KM-6 - there can be 1 or 2 types, KM-3 - only 2 types.

Design options:

— non-isolated, multi-directional outputs: KM-3a, KM-4a, KM-5a
— non-isolated, unidirectional outputs: KM-3b, KM-4b, KM-5b
— isolated, unidirectional outputs: KM-3b, KM-4b, KM-5b, KM-6(a, b)
— unprotected: KM-3v, KM-4v, KM-5v

Range of nominal capacities:

KM-3 680 pF - 22 nF
KM-4 16 pF - 47 nF
KM-5 16 pF - 0.15 µF
KM-6 120 pF - 2.2 µF

Distribution of CM by rated voltage value (V) and TKE groups:

Application

KM capacitors are designed for operation in DC, AC and pulsed current circuits. Used in any electronic equipment: household appliances, communication systems, measuring and scientific equipment, industrial equipment, etc.

Precious metals in KM capacitors

The use of materials such as palladium, platinum and silver in capacitors is determined by technological requirements and has a rational basis.

Structurally, capacitors are made of ceramic dielectric with a thin layer of metal applied to it on both sides (capacitor lining). The technical and operational characteristics of the capacitor depend on the selected material of the dielectric and plates.

Special ceramics based on calcium, zirconium and barium titanate are used as a dielectric. Technologies make it possible to obtain ultra-thin layers of dielectric and assemble them into sandwiches. This provides low electrical conductivity, capacitance capacitances from fractions of picofarads and rated voltages over a wide range.

Depending on the technology used for applying metals to the dielectric, the use and content of one of these precious metals in the capacitor plates varies. Given the technological requirement for high ceramic firing temperatures, the use of silver is limited and palladium and platinum are used more.

Interesting information: it turns out that of the total volume of palladium that is needed for the electronics industry, the share of palladium used for the production of ceramic capacitors can reach up to 60%.

Taking into account the fact that capacitor production technologies were mastered sequentially, based on technical requirements, the content of these precious metals in capacitors should depend both on the plant and on the year of their production.

As mentioned above, the content of ceramic capacitors in used electronic equipment can reach up to 20% of the number of components, and in some products - even higher. The problem of recycling waste from the electronics industry today is actually an unsolved problem. In this regard, there are quite a large number of offers on the market calling for the collection and disposal of unusable electronic devices.

For KM ceramic capacitors, lists have been compiled with characteristics that determine the type of capacitors and their approximate value. The contents of these “lists” may differ from each other, but there is a commonality of certain parameters by which the value of a particular type of KM capacitor can be determined.

Below are some groups of offers from different capacitor buyers. In the “Marking example” column, the “/” sign indicates the separation of the lines of inscription on the capacitor body itself.

There are also simpler lists without indicating values,
but only with a listing of what is accepted, for example:

The linear dimensions of KM capacitors depend on the design option, nominal capacitance and TKE group (dimensions in mm, from min. to max.):

Green, thin - from 3x3x0.3 to 13x13x3;
- red, thick, 1MF, 2*2MF, N90, 1M0, 2M2 - from 14x14x6 to 14x14x10;
- red, thick, others - from 6.5×6.5×4.5 to 14×14×6.

A certain difference in proposals can be explained by individual conditions and business characteristics. The absolute values ​​of prices for precious metals depend on many parameters (including prices on exchanges) and there is no point in citing them at any specific point in time.

The Astrea-Radio Components company buys the following series of capacitors at competitive prices:

• Monolithic ceramic capacitors of the following markings: KM3, KM4, KM5 N90 green, KM5 N30, KM6 N90, KM6 N30 red, K10-17, K10-26, K10-48.
• Frameless capacitors made in the USSR, new and used, prices and photos in the catalog. Do not mix imports, you can see right away.
• Imported capacitors of certain markings, see the catalog with photos and prices.
• We currently do not buy imported frameless capacitors.
• Capacitors in a plastic case: K10-17, K10-23, K10-28, K10-43, K10-46, K10-47.
• Soviet-made tantalum capacitors of the following series: K52-9, ET, ETN, K53-1, K53-7, K53-16, K53-18, K53-28.
• Capacitors K10-7 "red flags", K15U-1, K31-11, K50-6, K50-12, K53-4, K53-14, K53-21, K71-7, K73-3, K73-17, K78 -2 and similar ones are not suitable, we do not buy these at present. The content of precious metals in these capacitors is low or absent.
• Silver-tantalum capacitors: K52-1, K52-2, K52-5, K52-7, ETO-1, ETO-2.
• Capacitive assemblies B-18-11, B-20, pass-through filters B-23, MLZ delay lines, micromodules, GIS.

We buy the listed series of capacitors containing precious metals in any condition, new or used. We also purchase imported capacitors for scrap. Various series and types of accepted capacitors, including imported capacitors, are presented in our volume.

All you have to do is compare your parts with photo samples of capacitors on the website and find out the exact price for each type. Separately, it is worth highlighting the purchased capacitors KM3, KM4, KM5, KM6 (popularly “kaemki” or “KMki”), containing rare-earth precious metals such as platinum and palladium. Silver in KM capacitors is contained in small quantities, so it does not affect the final price. In different series, the content of platinum and palladium is different, therefore, each type of KM capacitors has its own price per gram, which changes every day. Prices and photos with markings of capacitors KM3, KM4, KM5, KM6 are in the catalog. Undoubtedly, KM capacitors top the rating of the most expensive and valuable radio components of the USSR.

These KM capacitors come in different colors in appearance. The most common colors: green, red, brown. KM capacitors in yellow, light green and blue colors are also quite common. KM capacitors painted blue are one of the very first productions launched in the USSR, in 1962-1963 of the last century.

The nominal values ​​and characteristics on the case were not yet printed in numbers, but were marked with two colored dots. Also, by the color of the dots, you can determine which group, H90 or H30, a particular capacitor belongs to. Green KM capacitors of the H30 group are usually square in shape, up to 1 mm thick. The H90 group is much thinner and generally rectangular in shape. Also, the H30 and H90 groups were painted in different shades of green.

There are two more groups of green KM capacitors:

1. A group with the Latin letter "D" in its markings. They are 20% cheaper than the H30 group due to lower content.
2. A group with the Latin letter "V" in its markings. They are 20% more expensive than regular H90s. Only large capacitors marked “5V” are accepted at a higher price.

KM6 capacitors are mainly red in color. They resemble “pads” in shape. The most common group of red capacitors is KM6 N90. But quite often there are also groups KM6 H30, H50, D, E. All types of KM capacitors are presented in our photo catalog with updated prices, after studying which you will know exactly which capacitors are accepted for scrap and at what price. Selling KM capacitors is not a problem, the point is at what price you will sell this or that group or mixture consisting of H90 and H30, or capacitors with uncut leads. For example, purchases of radio components in Omsk or Chelyabinsk offer a price for KM capacitors of only 30% -40% of our price. Therefore, many people living in these cities and nearby regions send various suitable radio components by parcel to our company.

If you lack time or have doubts about correct sorting, then entrust this matter to professionals. Our specialists will process them themselves, sort them into groups and calculate the price of capacitors based on them; the cost will not change downwards.

Absolutely everywhere there are advertisements “buying radio components”, “I will buy expensive radio components”, “I will buy Soviet transistors, microcircuits, capacitors and blah blah blah...”. But why, who needs these outdated microcircuits, large transistors, lamps, capacitors?

I think most people are already aware - precious metals are gold, silver, platinum, palladium. Yes, yes, that is why people who are far from radio engineering and electronics buy them in kilograms. Let's start with the most expensive elements. I present to your attention capacitors.

Attention, the article was written back in 2013. Now prices are many times higher!

KM-N30.

The price for 1 kg of such capacitors reaches up to 70,000 rubles! Think about this amount 0_0. If you collect 2 kilograms of these condensers in a year, you can not work for a whole year :-). And I’ll tell you a secret that some people do just that. Some grandmother or grandfather has an old Soviet radio, an antediluvian TV or radio lying gathering dust. Buyers go from house to house and buy up this equipment for pennies, and sometimes even for nothing, and, of course, bite off and solder off expensive radio elements. But why are these capacitors the most expensive? They contain the most expensive precious metals - platinum and gold.

Prices at the end of 2012 for precious metals: gold - 1620 rubles per gram, silver - 30 rubles per gram, platinum - 1500 rubles per gram, palladium 700 rubles per gram. Prices are slightly rounded for ease of perception. Such capacitors contain the most platinum, according to the Internet, up to 20 grams per 1000 pieces. Now they are quite difficult to find.

Also from this series are capacitors KM-5D. Their price can reach up to 40,000 rubles per kilogram.

Also of great interest are red condensers KM-N30. Their price reaches up to 35,000 rubles per kilo.

And like this, so that it says N902M2. Their price up to 30,000 rubles per kilo.

As you can see, the price range of capacitors greatly depends on how many milligrams of precious metals are contained in each of them. They also accept a lot of types of other capacitors, but I think you shouldn’t bother with them, since their price is a penny.

To summarize, buying radio components consisting of green and red capacitors is a profitable business.

Precious metals in microcircuits

There is such freedom here. 99% of any microcircuits are purchased. They can be in round, ceramic, planar, or metal cases. But, I think it would be more advisable to focus on the most highly profitable microcircuits. There is only one rule here: if it smells of gold, then such a microcircuit is accepted without any problems. These may be gold-plated contacts or a housing. So, I present to your attention the highest paying microcircuits:

133LA1 – up to 12 rubles per piece

133LA8 – up to 26 rubles per piece

542ND1 – up to 28 rubles per piece

K5ZhL014 – up to 55 rubles per piece

K5TK011 – up to 55 rubles per piece

Keep in mind - these are just some of their names. The microcircuits may be completely different in name, but if it is similar to the microcircuits that I showed in the photo, then they will also be accepted for the same price. As you can see, their terminals and housings are gold plated. In short, if you see any of this, immediately take care and save it ;-). This also includes computer processors.

In the photo below are microcircuits that are accepted for a good price, regardless of what is written on them. The golden color makes itself felt.

The remaining microcircuits are not worthy of attention as a sale for precious metals, since they cost pennies, so let’s move on to the next group of radio components.

Precious metals in transistors

Let's also consider the most expensive of them.

KT909A-B – up to 30 rubles per piece

KT904,907,914 are “sharpened” for a yellow bolt – up to 40 rubles per piece

KT970A – up to 30 rubles per piece.

KT602-604 and the like with yellow legs. Price per piece – up to 30 rubles.

As you noticed, all presented transistors are gold plated.

Other radio components

Variable resistors are in great demand. Their price varies from 5 to 10 rubles per piece.

Some types of relays. For example RES-7. Its price is up to 500 rubles per piece.

Only certain types of relays of certain years and series are accepted. Anyone who still wants to hand over relays, I advise you to scour the internet and know exactly which relays of which year are accepted.

And, of course, there are connectors with gold-plated contacts. If you see a yellow glow on such connectors, you can safely return them. Prices here can also vary from 50 kopecks to 3 rubles per contact. Multiply the price by the number of contacts - that’s the price of the connector.

And also Soviet lamellas for about 1000 rubles per kilo. For those who don’t understand what lamellas are, remember the Dandy cartridge :-)

Summary

Buying radio components is a profitable business. If there are outdated parts and they are lying around idle, then of course it would be better to get rid of them and at the same time get some good money. But you shouldn't be a fanatic about this matter. After all, you and I are electronics engineers – good, kind people :-). Don't give in to greed. Maybe these radioelements will bring you more benefit than melting them down into precious metals. You shouldn’t turn around grandpa’s working radio or grandma’s latest TV in pursuit of money. Explore the world of electronics, don't get rid of it. All that glitters is not gold.