Faults of electronic components Precautions for using electronic components

Electronic component order is a term in the field of components, but many friends do not understand what is electronic component order.??In order to improve our understanding of electronic component allocation, this paper will introduce electronic component allocation and the matters needing attention in using electronic component allocation.?

Although there are many electronic components in electrical equipment, their failures are regular.?

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1. Characteristics of resistance damage?

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Resistors are the most abundant component in electrical equipment, but not the one with the highest damage rate.??Resistance damage with open circuit is most common, resistance increase is rare, resistance decrease is very rare.??Common carbon film resistance, metal film resistance, wire wound resistance and insurance resistance.?

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The first two kinds of resistance is the most widely used, the characteristics of the damage is a low resistance (below 100 ω) and high resistance (more than 100 K ω) damage rate is high, the middle resistance (such as hundreds of euros to tens of thousands of euros) very little damage;??Second, when low resistance is damaged, it is often scorched and black, and it is easy to find, while there are few traces when high resistance is damaged.?

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Wire wound resistance is generally used for high current limiting and has small resistance.??When the cylindrical wire wound resistance is burned out, some will be black or surface skin, crack, and some have no trace.??Cement resistors are a type of wire wound resistors and may break when burned out, otherwise there is no visible trace.??When the resistors burn out, some surfaces will blow off a piece of skin, others will have no marks, but will never burn black.??According to the above characteristics, in the inspection of resistance can be focused on, quickly find out the damaged resistance.?

2. Characteristics of electrolytic capacitor damage?

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The amount of electrolytic capacitor in electrical equipment is very large and the failure rate is very high.??Electrolytic capacitor damage has the following performance: one is completely lost capacity or smaller capacity;??Two is slight or serious leakage;??Three is the loss of capacity or smaller capacity leakage.??Methods for finding damaged electrolytic capacitors are:?

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(1) Look: some capacitor damage will leak, capacitor below the circuit board surface and even capacitor appearance will have a layer of oil stains, this capacitor must not be used;??Some capacitors will swell up after damage, this capacitor can not continue to use;?

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(2) touch: after the boot, some serious leakage electrolytic capacitor will heat up, or even hot when touched by your finger, this capacitor must be replaced;?

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(3) There is electrolyte inside the electrolytic capacitor, long time baking will make the electrolyte dry, resulting in reduced capacitance, so it is important to check the heat sink and the capacitor near the high-power components, the closer it is, the greater the possibility of damage.?

3. Damage characteristics of second and triode semiconductor devices?

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The damage of two or three audions is generally the breakdown or open circuit of PN junction, in which the breakdown short circuit is the majority.??In addition, there are two kinds of damage performance: one is poor thermal stability, performance is normal when the boot, after a period of time, soft breakdown;??The other is that the characteristics of PN junction is worse, measured with a multimeter R× 1K, the PN junction is normal, but can not work normally after the machine, if using R×10 or R×1 low range file measurement, it will find that the PN junction forward resistance value is larger than the normal value.?

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The measurement of two or three audions can be measured with a pointer multimeter on the road, the more accurate method is:??Put the multimeter in R×10 or R×1 (R×10 is generally used, and R×1 is used when it is not obvious) to measure the positive and reverse resistance of THE PN junction of the second and triode on the road. If the forward resistance is not too large (relative to normal value) and the reverse resistance is large enough (relative to positive value), it indicates that the PN junction is normal, otherwise it is doubtful and shall be tested after welding.??This is because the peripheral resistance of two or three audions in general circuits is mostly above several hundred or several thousand ohms, and the influence of the peripheral resistance on the RESISTANCE of PN junction can be basically ignored when the multimeter is used for road measurement with low resistance.?

Second, what is the list of electronic components?

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An electronic component order is a complete BOM given by the customer, which contains multiple types of electronic components, and then helps the customer to complete the required part numbers in the list.??According to the models and forms provided by customers, we need to quickly, reasonably, honestly and honestly solve the problems of too many varieties to buy original authentic products and high prices for customers.?

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Therefore, electronic components ordering must provide professional, efficient, one-to-one electronic components ordering services, to solve the most fundamental needs of customers and reduce production costs, improve effectiveness.?

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Three, the use of electronic components with notes?

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1. After receiving a BOM form from the customer, carefully review the BOM and confirm the specification requirements.??Reply speed should be fast, confirm specifications and models, carefully check, not sure to timely communicate with customers.?

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2. When quoting to the customer, be sure to ask whether the customer wants to issue an invoice, confirm when the customer wants to buy, whether it is an inquiry or an order.?

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3. Talk about the terms of payment, delivery on delivery, payment on delivery or monthly payment.??Next, we need to follow up whether the customer has received the goods and the arrival situation.??The whole process of electronic components ordering needs to let customers experience professional, efficient, fast and high-quality service.?

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In short, electronic components distribution is to help customers professional, efficient, fast, quality to solve the procurement of electronic components of various categories.?