Recognition method of chip resistor

SMD resistors are also business card type fixed resistors, which are one of the metal glass glaze resistors. It is a resistor made by mixing metal powder and glass glaze powder and printing it on the substrate by screen printing. It is resistant to humidity and high temperature, and has a small temperature coefficient. It can greatly save the cost of circuit space and make the design more refined. It has small size, light weight, high installation density and strong shock resistance. It has the advantages of strong anti-interference ability and good high-frequency characteristics. It is widely used in computers, mobile phones, electronic dictionaries, medical electronic products, camcorders, electronic watt-hour meters and VCD players.

There are 3 ways to identify the chip resistors, namely, the nominal method of digital cable position, the nominal method of color circle, and the nominal method of mixed number code and letter.

Digital Cable Nominal Method

The digital cable position nominal method uses three digits on the resistor body to indicate its resistance. Its one and two digits are significant digits, and the three digits indicate the number of "0" added after the significant digits. No letters will appear in this one. For example: "517'" means "510000000Ω"; "342" means "3200". If it is a decimal, use "R" to mean "decimal point". It occupies one significant digit, and the remaining two are significant digits. For example: " R45" means "0.45Ω"; "1R5" means "1.5R". There are also 4 digits notation, the first three digits are effective digits, and the fourth digit is the magnification. 2702=27000=27kΩ?

Color circle nominal method

SMD resistors are the same as general resistors, and most of them use four rings to indicate their resistance. The first ring and the second ring are valid numbers, and the third ring is the multiplier. For example: "brown green black" means "15Ω"; "blue gray orange silver" means "68kΩ" error ±10%.

Number code and letter mixed nominal method

The number code and letter mixed nominal method also uses three digits to indicate the resistance value, that is, "two digits plus one letter", and the two digits represent the E96 series resistance code. Its third digit is the magnification expressed by the letter code.