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In this lesson,

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we talk about the electricity leakage and the maintenance of electricity protection

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We mainly focus on the following aspects

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First, the power supply current of the normal mobile phone

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Second, the understanding of the word connection leakage

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Third, the related circuit of connection and leakage

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Fourth, the related circuit of power connection protection

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Fifth, how do we generally maintain

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Let's look at the normal current of a machine

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We adjust the voltage to 4.2V

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and used the power cord to supply power to the battery holder

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At this time, there is no current,

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indicating that this is a normal mobile phone,

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and all normal mobile phones are like this

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Supply power to the positive pole of the battery,

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without pressing the power button, it cannot have current here

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Let's take a look at the understanding of the phenomenon of power leakage

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For a normal mobile phone mainboard,

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the DC power supply set the output voltage to be 4.3V

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Use the power cord to supply power to the mainboard battery holder

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At this time,

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the current of the DC power supply will display 0 mA,

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which is also called no current response

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For a leaky mainboard,

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after adding 4.3V of power to the battery holder,

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without pressing the power button,

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the current display of the DC power supply shows a certain current,

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which may be several mA,

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some tens of mA,

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a few hundred mA

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We should also note that this current is basically fixed here,

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This phenomenon is called leakage current

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Let's take a look at the specific phenomenon of this power leakage

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We adjust the DC power supply to 4.2V,

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and as soon as we turned on the power

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its current ran to 422 mA,

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Its current is always set at this number

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We call it leakage 422 mA,

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also called connection leakage 422 mA

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Which circuits and components are directly related to the leakage of electricity?

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Let's take a look

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The positive pole of the battery generates power,

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which is supplied to the charging chip,

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which is converted into the main power supply,

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and then the main power supply is supplied to the power chip,

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display chip, WiFi chip, and RF power amplifier, etc.

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So what circuits are connected to the leakage current?

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All lines to which the positive battery goes and all lines to which the mains supply is connected

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Any damage to any component on the line may cause electricity leakage

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Okay, that's it for this lesson