Knowledge of resistors

1. What is resistance

The action of stopping the current is called resistance. A device with a certain resistance value is called a resistance element. The R(Resistor) is expressed in English.

2. Resistance unit

The basic unit for ohm Ω its extension units have thousand o K Ω megohm M Ω

3. Conversion formula of measurement units:

1 m Ω = 10 ³ K Ω = 10 ⁶    Ω

4. Type and structure of resistance:

4.1 Material classification:

CF:Carbon Film

TF:Thick Film

MF:Metal Film

Wirewound

4.2 Classification by structure:

Fixed resistance. (R)

Semi-adjustable resistance. (S-VR)

Variable resistance (VR)

4.3 Classification by shape:

Color ring resistance

Sheet resistance.

exclusion

4.4 Classification according to rated power:

1/16W, 1/8W, 1/4W, 1/2W, 1W, 2W, 3W… And so on.

Power can be distinguished by its shape and size. The larger the volume, the greater the power.

5. Main characteristics of resistance:

The main technical parameters of resistance include resistance value, rated power, error range and so on.

6. Resistance representation method:

The resistance values and errors of resistors can generally be represented by digital marks printed on the resistors or by color rings. Only numerical representations are described below.

Using three digits:

SMT resistors with an error of 5% are typically printed on the resistor by a three-digit number, with the first two digits representing significant digits and the third digit representing a multiple of 10n.

Is represented by three digits:

Precision resistors are usually represented by four digits, the first three significant digits and the fourth power 10n.

less than 10 Ω resistance with the letter “R” and the two Numbers:

5R6 = 5.6 Ω    3R9= 3.9 Ω   R82  = 0.82Ω

Exclusion of SMD type:

Usually expressed by RP××, for example, 10K OHM 8P4R means that the 8 pins are composed of 4 independent resistors, and the resistance value is 10K OHM exclusion.

NeoDen provides a full SMT assembly line solutions, including SMT reflow oven, wave soldering machine, pick and place machine, solder paste printer, Reflow oven, PCB loader, PCB unloader, chip mounter, SMT AOI machine, SMT SPI machine, SMT X-Ray machine, SMT assembly line equipment, PCB production Equipment SMT spare parts, etc any kind SMT machines you may need, please contact us for more information:

Hangzhou NeoDen Technology Co., Ltd

Web: www.smtneoden.com

Email: info@neodentech.com