Do you know resistance, chip resistance and its resistance value?
Resistance belongs to the basic components of the basic components, which a large number of existing in ATX power circuit boards.
The resistance commonly used on ATX power circuit board is direct insertion (color ring) or patch carbon film / metal film resistance. If the stone wish or all is made into a specific three-dimensional carbon film / metal film (actually attached to a cylindrical/flake ceramic skeleton), a variety of resistance values can be obtained cheaply.
On the surface, resistance is just one of the simplest two-terminal components, and mastering it should not be particularly difficult. But practice has proved that the simpler the thing, the less likely it is to be really mastered. The difficulty encountered in learning resistance lies not in its discrimination, measurement and judgment, but in distinguishing circuits, finding equivalent test points, and defining the circuit process related to them. These links are also important to pay attention when learning other basic components. It can be imagined that if we can distinguish the basic components (such as the packaging size of resistance, parameters, etc.) can achieve the purpose of distinguishing different circuits and finding equivalent test points, certainly provide a lot of convenience for the maintenance operation. This ability of analyzing circuits at a glance actually reflects that our level of understanding of the circuit as a whole. This is a relatively high level of skill.
Most of the patch resistance used in ATX power supply is 0805 or 1206 packages. The resistance of this package is already a larger resistance in all patch resistors, and the surface space is enough to print the three digit or four-digit combination that identifies its resistance parameters. Manufacturers usually print a digital combination of three-digit or four digits on the back of the patch resistance to describe the resistance value of the patch resistance. For the combination of digits, we put 100 digits as A and 10 digits as B. C. Then AB is the valid number in the positive value of the patch, and c is the number of 0 that should be added after the valid number. Therefore, the actual resistance value of the resistance is AB*10c. If the combination of three digits on the back of a patch is 472, the resistance value is 47 * 10*10 =4.7 k Ω. And so on.
For the four-digit combination, we make a thousand digits A. One hundred is B, ten is C. If the number is D, then ABC is the valid number in the positive value of the patch, and D is the number of 0 that should be added after the valid number. Therefore, the actual negative value of the resistance is ABC-10D. If the bit number combination on the back of a patch resistance is 1001, the resistance value is 100 * 10 = 1k Ω, and so on.
If the patch resistance is called 1RO, 2R2, etc., then R means a small number and the dimension is Ω. The resistance value of 1R0 is 1.0 Ω, the resistance value of 2R2 is 2.2 Ω, and so on.
If you want to know more, our website has product specifications for resistor, you can go to ALLICDATA ELECTRONICS LIMITED to get more information