The marking of resistors is three main methods

Everyone who was engaged in the repair of electronic equipment, knows that sometimes it is necessary to determine the appearance of the resistor its denomination. The easiest way is to measure the resistance with an ohmmeter, but the trouble is, there is not always an opportunity to drop it without damaging the circuit board, especially multilayer, and sometimes there are doubts about the integrity of internal contacts. If there is a circuit, everything is simple - you can look into it and see that R18 is, for example, 47 Ohm. And if it's not there, but you need to figure it out, and you'll have to draw the diagram yourself?

Fortunately, manufacturers of electronic components have agreed among themselves, and there is a standard marking of resistors. True, it has undergone changes over the past decades.

The most common in our time is the color marking of resistors. It is very simple, and to read the denomination, holding a simple cardboard decoder, it's a matter of seconds. This device is widely available, there is in any radio store and it is very cheap, so remember the color values are not worth it. The marking of resistors consists in the fact that the resistance is painted with a ring of different colors, each of which means a digit, multiplier or degree of accuracy.

Strips are available from three to five. Read them should be from the first, located closer to one of the conclusions. For example, there are four bands. The first - brown, the second - black, the third - red, the fourth - gray. You should dial these colors on the decoder, skipping the third one (there you should select the "no" position). Done, this is 1 kΩ with an error of 0.05%. If the bands are three, the accuracy is 20%.

Sometimes it becomes necessary to deal with the old Soviet technique, still in use. Once it was scolded, it seemed clumsy and ugly, but time showed the amazing vitality of some samples of this equipment, and it is now even sometimes called "vintage". The marking of Soviet-made resistors is even simpler than color, they just write a denomination, for example, 4K7 means 4,700 ohms. And that's all. Simply and clearly. One drawback - this inscription can appear from below, Soviet radio plants very rarely used "standing" mounting of resistances, it was loved by the Japanese to save space on the board.

The miniaturization of electronic equipment has placed its manufacturers before the need to invent new ways of installation. Classical soldering of resistors through holes on the board in the "standing" or "lying" position takes up too much space, and now there is a new way of assembling microboards - smd. In this English abbreviation, three words are ciphered: "surface" is the surface, "mount" is editing, and "technology" is clear, which means. Small parts are soldered directly to the track on the surface, without holes and legs. It took a new marking of resistors, and other components, such as diodes and capacitors, too.

Marking smd resistors is somewhat reminiscent of the good old Soviet way. They also printed numbers and letters. The difference is still there. The letter is not always, if necessary, "R" is used as a dividing point.

For example, 2183 means that 218 needs to be multiplied by 1000, 218 kΩ is obtained. Resistance with a tolerance of up to 10% is marked with four digits, the latter means the degree to which the ten is to be built, and multiply by this result a three-digit number formed by the first two digits.

Slightly more difficult with smd resistors of higher quality, with a tolerance of 1%. Here the degree of the tens is given by a letter, for example, D is 10 in a cube. If the resistance is 10D inscribed, this means 10 kOhm.

In addition to the correspondence tables, the repairman will need a magnifying glass, since the symbols are very small!