Which parameters are required to pay attention to in the purchase of the patch pressure sensitive resistance parameters
What are the parameters of the patch? What are the five parameters that need to be noticed in the purchase of a voltage sensitive resistor? In this paper, the patch parameters and the five parameters of the chip resistors are described. In the hope of understanding the parameters of the patch pressure sensitive resistance, the five parameters are also increased.
Parameters of chip varistor is typically expressed in the letter "my", such as home and j said, behind the letter W, G, P, l, h, Z, B, C, N, K respectively for voltage regulation, overvoltage protection, high frequency circuit, lightning protection, arc, eliminating noise, compensation, degaussing, high energy and high reliable aspects.
In recent years, in addition to the development of electronic products with the development of new products, the development of new products, maintenance personnel also began to repair a large number of electronic products SMT technology assembly.
This article will introduce the application of the maximum size of the patch resistance, capacitance and inductance of the main parameters and specifications, in order to develop personnel, maintenance personnel to buy these patch type components to help.
Current patch resistance model is not uniform, by the manufacturers to set their own, and models of special length (by more than a dozen letters and figures in English). In the purchase, if the correct way to put forward a variety of parameters and specifications of the patch, it can be very convenient to buy (or order) to the required resistance.
There are 5 kinds of chip resistor parameters, namely size, resistance, tolerance, temperature coefficient and packaging.
1 size series of patch resistance series generally have 7 sizes, with two kinds of size code to say. A size code is the 4 digit representation of the EIA (American Electronics Industry Association) code, the first two and two respectively, the resistance of the long and wide, in inches as the unit. The other is a metric code, also expressed by the number of 4, the unit is mm. Different sizes of resistance, the power rating is also different. Table 1 lists the codes and power ratings of the 7 types of resistance.
The 2 series is based on series resistance nominal resistance is determined. The series is by resistance of the status of the poor to divide (tolerance smaller is resistance divided more), of which the most commonly used is E-24 (resistance value of permissible deviation of + 5%), as shown in Table 2.
Patch resistance parameters on the surface with three digits to represent the resistance, which first and second place effective number, said the three digit connected number of zero. Use "R" to indicate when there is a decimal point, and a valid digit. Nominal resistance code method as shown in table 3.
3 tolerance of the chip resistor (carbon film resistance) tolerance of 4, that is, F, G, l%, + 2%; J, + 5%; K, + 10%.
4 the temperature coefficient of the patch resistance temperature coefficient is 2, that is, W, + 200ppm / C, X, + lOOppm / C. Only the tolerance for the F level of resistance to the use of X, the other level of resistance is generally W.
5 packing mainly has two kinds of bulk and strip rolling.
The working temperature range of the patch resistance is -55--+125, the maximum operating voltage is related to the size: 0201 minimum, 0402 and 0603 for 50V, 0805 for 150V, and other sizes 200V.
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