In the design and manufacturing of modern electronic equipment, resistors, as basic electronic components, play an indispensable role. This article will delve into the characteristics of various typical resistors and their application areas, thereby providing professional guidance for the selection and application of electronic components.
Basic properties and applications of metal film resistors
Metal film resistors are a common type of resistor in electronic manufacturing. They are characterized by their small size and thin resistive film, which makes their application in circuits very flexible. The temperature coefficient and aging performance of this type of resistor are average, but its 1% accuracy can be guaranteed in the range of high resistance values (greater than 1MΩ) and low resistance values (less than 5Ω). This balanced performance makes metal film resistors widely used in common electronic equipment, especially where extreme accuracy is not required.
Comparison between green robe resistor and red robe resistor
Green robe resistor, a metal film resistor that appeared in the mid-to-late 1980s, is named after its dark green appearance. Although it has been widely used in some specific applications (such as MF12 and MF14 multimeters), according to actual tests, there is a significant gap in its performance compared with red-robed resistors in terms of aging, deviation and temperature coefficient. On the contrary, Hongpao resistor is famous for its precision metal film characteristics of high stability and low temperature coefficient. It is larger in size. After long-term testing, its aging rate is extremely low. It rarely changes by more than 0.5% over the years. The temperature coefficient remains at About 30ppm/℃. This high performance makes Hongpao resistors particularly suitable for electronic equipment requiring high precision and stability.
Classification and performance of wirewound resistors
Wirewound resistors can be divided into ordinary wirewound resistors and precision wirewound resistors according to different manufacturing materials and processes. Ordinary wirewound resistors usually use manganese copper or constantan resistance wire and have a non-sealed design. They have good aging performance, but the temperature coefficient is relatively high (15ppm/℃ to 35ppm/℃). The precision wire-wound resistors are made of precision manganese-copper materials. Through sealing treatment, their stability is greatly improved. Most of them can still maintain an accuracy of 0.02% after several years of use, and the temperature coefficient has also reached a high level. level (5ppm/℃ to 20ppm/℃). This precision wirewound resistor is widely used in high-precision measurement and control systems.
Low temperature coefficient (TC) wirewound resistors and fully sealed wirewound resistors
Low TC wirewound resistors are widely used in old foreign precision instruments, such as Fluke brand equipment, because of their extremely low temperature coefficient (1ppm/℃ to 5ppm/℃). This type of resistor uses nickel-chromium resistance alloy, which has excellent aging performance. The annual aging rate is usually within 20ppm/year, so it is very suitable for use as a standard resistor. Fully sealed wire-wound resistors use the same materials, but are sealed by a metal shell to further improve stability (reaching about 8ppm/year), and the temperature coefficient is mostly within 1ppm/℃, which makes them more suitable for older generation high-level measuring instruments. and standard resistors are widely used.
Advanced Applications of Plastic Block Resistors and Gold Block Resistors
Plastic block resistors and gold block resistors represent high-end applications of resistor technology. Plastic package resistors use nickel-chromium resistance alloy and compensation technology to achieve extremely low temperature coefficients (less than 1ppm/℃). Although their aging characteristics are not as good as metal package resistors due to poor sealing performance, they can still meet the requirement of 25ppm/year. Stability requirements, often used in high-end audio equipment. Gold block resistors are the top design in resistor technology. They use cermet sealing technology to completely isolate external aging factors. Its zero temperature coefficient technology even makes the temperature coefficient difficult to measure. The aging rate can reach 2ppm/year, and some high-quality products are even as low as At 0.5ppm/year, this resistor demonstrates unparalleled performance in high-precision measurement and standard resistance applications.
Through the above analysis, we not only gained an in-depth understanding of the characteristics of various types of typical resistors, but also discussed their advantages and limitations in different applications. This knowledge is critical for selecting appropriate resistors during electronics design and manufacturing, ensuring maximum device performance and long-term stability.