The reason that resistor damages reachs judgement method

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Resistor attaint has two kinds of reasons commonly: External, in-house. External the reason has a lot of, electric current is too big, bring about burn down or be block value change. Soldering circuit board because of outside force action, produce deformation, make resistor ruptures thereby (stick resistor in the watch especially in the commonnest) . Calorific quantity of heat cannot although eduction, make resistor works to damage easily also in the environment of overheat... internal matter has a few kinds commonly: Resistor quality is coarse, material is inhomogenous, bring about local resistance to produce change. Power chooses very stand by most high-power dot, when the instant is disturbed, resistor damages... resistor is the component with the maximum amount in wiring, but not be the component with attaint top rate. Resistor damages with open circuit the commonnest, block value greatens scarcer, block value decrescent is very scarce. Resistor of common film having carbon, metallic film resistor, line circles resistor and insurance resistor a few kinds. Before two kinds of resistor application are the widest, the characteristic that its damage is low block value (100 Ω are the following) be worth with tall block (100k Ω above) attaint rate is higher, intermediate block is worth (if hundreds of Europe go to a few Europe) few attaint; 2 it is low block when resistor damages, the value often is to scorch nigrescent, discover very easily, and there is a mark rarely when tall block is worth resistor to damage. The line circles resistor to use as commonly current limliting of big electric current, block value is not great. Cylindrical some meetings when the line circles resistor to burn out nigrescent or the surface explodes skin, crackle, some does not have a trace. Cement resistor is a kind when the line circles resistor, when burning out, may rupture, also did not see a mark otherwise. Meeting blast drops some surfaces when insurance resistor is burned-out a skin, some also does not have what trace, but won't scorch absolutely nigrescent. According to above characteristic, can emphasize particularly on somewhat when checking resistor, find out the resistor of attaint quickly. List the characteristic that go out according to above, we can observe low block is worth resistor to burn black mark on circuit board first, open a way of the great majority when damaging according to resistor again or block value greaten and the characteristic that resistor of tall block value damages easily, we can be with avometer on circuit board the block of two end is worth the resistance that estimates tall block value directly first, if measure the value that get block to compare nominal block value is great, criterion this resistor damages for certain (the ability after should noticing value waiting for block shows stability makes conclusions, component of because circuit is medium possible shunt-wound capacitance, one fills discharge process) , if measure the value that get block to compare nominal block value is little, need not pay attention to it commonly. Such is in on circuit board each resistor is measured, although " the fault is killed " 1000, also won't let off. CNC Milling CNC Machining