A resistor is the most common element embedded in any electronic circuit. It can be seen everywhere: from the simplest washing machine to a modern computer. Two types of markings are used to indicate their properties: the first is the color marking of resistors by applying multi-colored rings to the case, the second is alphanumeric.
Sign designation
On the cases of resistors and capacitors of relatively significant sizes, their nominal resistances (capacities) are marked using abbreviated standard designations of units, and next to them is the probable deviation from the declared nominal, for example: 1.5 Ohms 10%, 33 Ohms 20%. Such values ββare encoded in the color marking of the resistors. Encryption of nominal values ββof small-sized products consists of a special set of alphanumeric characters. But along with this, a mnemonic code is widely used today, that is, painted rings that make up the color marking of resistors. According to such a system, the unit of resistance is encoded by the letter Ohm (E), 1000 Ohm - as (K), megaohm - already (M). Nominal capacitances of resistors from 100-910 Ohms are designated in fractions of a kilo-ohm, and the range 100000-910000 - megaohm. In the case of expressing the nominal resistance as an integer, the letter designation is placed after the numbers - ZE (33 Ohms), 1M (1 MΞ©). Writing in decimal fractions less than one puts alphabetical marks in front of the number, for example, M47 (470 kOhm). And in the case of an integer with a decimal fraction, the letter is written instead of a comma after: 15 (1.5 Ohm), 15 (1.5 ). The permissible deviation always present is marked in the trace of the applied resistance: 5%, 10%, 15%. The color marking of the resistor can combine both types of markings.
Color marking
It consists in marking the outer shell of the device with the help of 3 or more colored concentric strips. Each method of painting carries a certain numerical value, revealing the properties of the resistance of the resistor. Usually, the last bar prescribes the value of the supposed tolerance of the product, and the first strips indicate resistance. For example, for markings with 4 stripes, the first two encode the size of the tank (Ohm), and the third serves as a factor for the mentioned value. The color marking of the resistors can be deciphered if you position the product so that the wide strip and all the rings following it are closer to the left hand. Then you need to use the comparative tables, which help to clarify the meaning of the differences.
Other standards
Color marking of imported resistors does not leave everything so clear. The fact is that for domestic products its own labeling is used, and for foreign products it is different. Some manufacturers even change the standards, creating their own color scheme. Unusual markings are used to distinguish those products that are manufactured according to the MIL requirements, which differ from industrial and domestic markings, can report fire resistance properties, etc. For example, the company "PHILIPS" indicates the value of the resistors as is accepted everywhere, i.e. the first numbers indicate ohms, and the last is a multiplier. Depending on the declared accuracy of the resistor, it is interpreted in the form of 3-4 characters. Differences from the usual encoding lie in the semantic load of 7, 8 and 9 of the last digits.