1. The structure and characteristics of common resistors. Commonly used resistors include carbon film resistors, carbon resistors, metal film resistors, wirewound resistors, and potentiometers.
Table 1 Structure and characteristics of several commonly used resistors
2. Nominal resistance and tolerance. Most resistors are labeled with the value of the resistor, which is the nominal resistance of the resistor. The nominal resistance of a resistor is often not exactly the same as its actual resistance. Some have larger resistance values, and some have smaller resistance values. The deviation of the actual resistance of the resistor from the nominal resistance, divided by the nominal resistance, is called the resistance error. Table 2 is the level of common resistance tolerance.
Table 2 The level of common resistance tolerance
The state has set a series of resistance values ​​as the standard for products. Resistors of different error levels have different numbers of nominal values. The smaller the error, the higher the nominal value. Table 3 is the nominal resistance series for common resistors. The nominal value in the table can be multiplied by 10, 100, 1000, ... such as 1.0 nominal value, there are 1 Ω, 10 Ω, 100 Ω, 1 k Ω, 10 k Ω, 100 k Ω, ...
Table 3 Ordinary fixed resistance nominal resistance series
Different circuits have different requirements for resistance errors. Generally, the electronic circuit can be used in Class I or Class II. In the circuit, the resistance of the resistor is generally marked with a nominal value. If it is not the nominal value, you can select the nominal resistance similar to it according to the circuit requirements.
3. The rated power of the resistor. When a current passes through the resistor, the resistor heats up due to power consumption. If the resistance heats up more than it can withstand, the resistance will burn out. The maximum power that the resistor is allowed to consume during long periods of operation is called the rated power. The power consumed by the resistor can be determined by the electric power formula:
Calculated, P represents the power consumed by the resistor, U is the voltage across the resistor, I is the current through the resistor, and R is the resistance of the resistor.
The rated power of the resistor also has a nominal value, and commonly used are 1/8, 1/4, 1/2, 1, 2, 3, 5, 10, 20 watts, and the like. In the circuit diagram, the symbol shown in Figure 2 is often used to indicate the nominal power of the resistor. When selecting a resistor, leave a certain margin and select a resistor whose nominal power is greater than the actual power consumed. For example, the actual load is 1/4 watt, and the 1/2 watt resistor can be selected. The actual load is 3 watts, and a 5 watt resistor can be selected.
4. The category and symbol of the resistor. In order to distinguish between different types of resistance, several Latin letters are often used to indicate the resistance category, as shown in Figure 3. The first letter R indicates resistance, the second letter indicates conductor material, and the third letter indicates shape performance. The figure above is the carbon film resistor, the figure below is the precision metal film resistor. Table 4 lists the categories of resistors and the technical characteristics of common resistors.
Table 4 Characteristics of resistors and technical characteristics of common resistors
5. Color ring resistance representation. The resistance and error of the carbonaceous resistor and some 1/8 watt carbon film resistors are represented by color circles. There are three or four color rings on the resistor. Close to the resistance end is the first color ring, and the rest are two, three, and four color rings, as shown in Figure 4. The first color ring represents the largest digit of the resistance, the second color ring represents the second digit, and the third color ring indicates that the resistance should not have a few zeros. The fourth color circle represents the error of the resistance. The numbers or meanings represented by the color of the color ring are shown in Table 5.
Figure 4
Table 5 The number or meaning represented by the color of the color circle
For example, there is a carbon resistor, which has four color rings in the order of red, purple, yellow, and silver. The resistance of this resistor is 270,000 ohms with an error of ±10%. For example, there is a carbon resistor, which has three color circles of brown, green and black. Its resistance is 15 ohms and the error is ±20%.
6. Mark the rules for the unit of the resistor and potentiometer in the circuit diagram. The resistance is above megaohms and the unit is marked M. For example, 1 megohm, marked 1M; 2.7 megohms, marked 2.7M.
The resistance is between 1 kΩ and 100 kΩ, and the unit is marked k. For example, 5.1 kilo ohms, marked 5.1k; 68 kilo ohms, marked 68k.
The resistance is between 100 kohms and 1 megohm, and the unit k can be marked or the unit M can be marked. For example, 360 kohms can be labeled 360k or 0.36M.
The resistance is less than 1 kohm and can be marked in Ω or not. For example, 5.1 ohms can be labeled 5.1 Ω or 5.1; 680 ohms, which can be labeled 680 Ω or 680.
7. General knowledge of the use of resistors. The type and error of the resistor should be selected according to the requirements of the circuit. In a general circuit, a carbon film resistor with an error of 10% or even 20% can be used.
The rated power of the resistor should be 1.5~2 times the actual power consumption to ensure the durability and reliability of the resistor.
Before the resistor is loaded into the circuit, verify its resistance with a multimeter ohmmeter. When installing, make the type of resistance, resistance and other symbols easy to see for verification.
ZGAR FILTER TIP
ZGAR electronic cigarette uses high-tech R&D, food grade disposable pod device and high-quality raw material. All package designs are Original IP. Our designer team is from Hong Kong. We have very high requirements for product quality, flavors taste and packaging design. The E-liquid is imported, materials are food grade, and assembly plant is medical-grade dust-free workshops.
Our products include disposable e-cigarettes, rechargeable e-cigarettes, rechargreable disposable vape pen, and various of flavors of cigarette cartridges. From 600puffs to 5000puffs, ZGAR bar Disposable offer high-tech R&D, E-cigarette improves battery capacity, We offer various of flavors and support customization. And printing designs can be customized. We have our own professional team and competitive quotations for any OEM or ODM works.
We supply OEM rechargeable disposable vape pen,OEM disposable electronic cigarette,ODM disposable vape pen,ODM disposable electronic cigarette,OEM/ODM vape pen e-cigarette,OEM/ODM atomizer device.
Vape Filter Tip,Disposable Pod Vape,Disposable Vape Pen,Disposable E-Cigarette,Electronic Cigarette,OEM vape pen,OEM electronic cigarette.
ZGAR INTERNATIONAL(HK)CO., LIMITED , https://www.szvape-pen.com