WRR-343 WRR-420 WRR-421 WRR-422 WRR-423 B thermocouples
WRR-343 WRR-420 WRR-421 WRR-422 WRR-423 B thermocouples, the correct selection and use of electronic components is an important condition to improve the technology, stability, reliability and safety of the entire electronic machine. Therefore, in the design of the whole circuit, a key link is the selection of components. There are thousands of manufacturers. Which one should I choose? There are thousands of components, which one to choose? There are dozens of component standards. Which one should I choose? There are many component performance parameters, how to choose? How to put forward the procurement BOM list simply and clearly? A large number of quality accident cases at home and abroad reflect the importance of this link. Once the wrong components are selected, they will have irreversible serious consequences. Then we should pay attention to the following issues that are easily overlooked when selecting resistors.
Resistor voltage and current are limited. When the voltage applied across the resistor increases to a certain value, breakdown will occur, resulting in an irreversible increase in resistance value or an open circuit. Therefore, the applied voltage must be limited. The breakdown of the resistor occurs between the two lead wires or between the spiral grooves. The breakdown voltage between the lead wires depends on the distance, shape, and ambient atmospheric pressure between the lead wires. The breakdown voltage between the resistor grooves depends on the groove width, the quality of the groove and the withstand voltage performance of the coated insulating material. The current value determined according to the rated power consumption and the nominal resistance value is the rated current.
As can be seen from the above formula: when the rated power consumption is constant, the smaller the resistance value is, the larger the rated current is. For low resistance resistors, the contact resistance accounts for a large proportion. The power dissipated here when the current passes The larger it is, at the same time, it is analyzed from the contact part. Due to the large current density in this part, local overheating is bound to eventually lead to early aging. In addition, if there are high-voltage electric pulses in the circuit, glass glaze resistors should be used. Rockchip provides a series of high-quality resistors such as carbon films, metal films, cement ceramics, and non-inductive resistors.