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Recognition and Measurement of Electronic Components

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This video mainly explains the identification of capacitor parameters

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and the application of capacitors

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capacitor parameters include position number,

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capacitance error, withstand voltage value, specification

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For example, in the picture, C8103 is the position number of the capacitor,

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and 0.22uF refers to the capacitance of the capacitor

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10% represents the error of the capacitor,

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6.3V represents the withstand voltage value of the capacitor,

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and 01005 represents the specification of the capacitor

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In the Android drawings, there are relatively few capacitors identifications,

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only the position number and capacitance value

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Capacitor application

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Capacitors are used in different circuits and have different names

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The most common one is the filter capacitor

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Generally speaking, it is to filter and select the waveform

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Capacitive filtering can also be understood as setting flood discharge areas at both ends of the river

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For example, there will be many flood discharge areas along the Yangtze River in China

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When the upstream water is too large to cause floods,

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in order to prevent damage to downstream properties,

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the gates of the flood discharge area will be opened

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Flood water will flow into the flood discharge area,

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and the water flowing downstream will be reduced

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If the floodwaters have not been reduced after the spillway is full,

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another spillway will be opened

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After passing through several flood discharge areas in this way,

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the flood will not cause damage to the downstream

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In this case, we can understand the flood discharge area as a capacitor

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In order to stabilize the working voltage of each chip in the mainboard,

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many capacitors are used to filter out the clutter signal

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The characteristic of the filter capacitor is that one end is connected to the line

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and the other end is grounded

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For example, in the picture, C1295 and C1296 are filter capacitors

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coupling capacitor

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Coupling capacitors are the basic characteristics of using capacitors to pass AC, block DC,

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pass high frequencies, and block low frequencies,

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and connect capacitors in series in the circuit

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After being connected in series in the circuit,

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the capacitor can couple the AC signal from the pre-stage circuit to the post-stage circuit,

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blocking the unwanted DC signal

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Coupling capacitors are characterized by not being grounded at both ends

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In mobile phone mainboards,

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this capacitor will be used in high-speed data transmission buses,

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such as PCIe buses

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For example, during the maintenance,

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we will find that coupling capacitors are used between the hard disk to CPU, baseband to CPU, and Wifi to CPU

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Because the signals transmitted between them are all high-frequency signals

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High-frequency signals are AC for capacitors,

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so they can pass through capacitors quickly

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Ok, that's all for this video