Don't throw away the electric kettle. It's easy to fix!

Electric kettle is believed to be one of the standard household appliances in many families , It is easy to use , After the water boils, the power can be cut off automatically .

However , The electric kettle is in use , It's easy to cause some faults and then it can't be used .

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Working principle of electric kettle

The circuit schematic diagram of general electric kettle is shown in the figure below , It's not complicated .

▲  Electric kettle circuit schematic diagram

When the steam switch is closed , The indicator light is on , The heating plate is energized to heat , When heated until the water boils, steam will be produced , When the steam blows into the steam switch, the metal sheet will expand and deform , Thus, the circuit is disconnected and the heating is stopped . The temperature control switch is normally closed , Only when the water is boiled dry will it be disconnected .

The products produced by different manufacturers may have some small differences , The circuit may vary , But the general principle is the same . Here are some key parts' functions and working principles .

1、 temperature control switch

temperature control switch , Also called thermostat 、 Dry burn protector , The temperature control switch is close to the heating plate , It is a normally closed switch , It is the key component of the hot water kettle .

▲  temperature control switch

The thermostat also serves as a connector , It can be connected to the base to turn on the electricity , The rings are fire wires 、 Zero line 、 Ground wire .

When the kettle is dry , The expansion and deformation of the metal sheet of the temperature control switch will push the rod , Thus, the contact of the temperature control switch is disconnected , Power off .

▲  Working principle of temperature controller for electric kettle

Normally, the contact of the thermostat is normally closed , After long use , Copper strip loses elasticity easily , As a result, the contact cannot be contacted and cannot be energized , This is a common fault of the thermostat .（ The thermostat often breaks ）

Want to check whether the thermostat contact is connected , You can check it with a multimeter , Terminal 1 Or it is connected with the big circle , Or it is connected with the small circle ; If terminals 1 It is connected with the big circle , Then the terminal post 2 It should be connected with the small circle , If it doesn't work , It means that there is a problem with the contact and it cannot be energized .

If the elasticity of the copper strip is poor, the contact cannot be contacted , Try bending the copper piece to make it contact in place , If the contact is still not accessible , Then you can only replace one thermostat .

The thermostat can be purchased online , The price is not high , Usually fiveorsix yuan a package , When purchasing, pay attention that the thermostat should be consistent with the original size , The key is that several screw holes should be consistent with the original , Just install it .

▲ The size of the thermostat should be the same as the original

Its coupling form doesn't need to be concerned , Just buy in pairs .

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2、 Steam switch

Steam switch , Turn this switch on when we boil the water , When the water boils, it will produce steam to the steam switch through the pipe , The steam switch is heated , The sheet metal will expand and deform , This causes the switch to open , Realize automatic power cut after water boiling .

▲  Steam switch

The steam switch is generally installed at the handle position of the pot body （ upper part ）, It can be measured without taking the handle apart , Want to know whether the steam switch is good or bad , You can check it with a multimeter like this .

▲ The resistance value should be zero when the switch is closed

In addition to this test , If the water does not automatically cut off power after boiling , Explain the steam switch （ Or ceramic thermostat ） There are also problems , It needs to be replaced .

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There is also a ceramic thermostat , It is installed on the inner wall of the electric kettle , To replace the steam switch . It directly detects the shell wall temperature , General parameters ：KSD301 220V/10A 92℃. The advantage of this form is that the steam will not affect the temperature control switch under the heating plate .

▲ Ceramic thermostat

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3、 Heating plate

The heating plate is the heating device of the electric kettle , Power on to generate heat , It is welded with the kettle , Generally, as long as the heating plate is not broken 、 The shell is not broken , Other devices are easy to replace , If the heating plate is broken, you can only throw it away .

Generally, the resistance value of the heating plate is 35Ω about .（ It seldom breaks ）

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Another is to combine the temperature control switch with the steam switch , The power switch is usually placed under the handle . The steam from the pot mouth enters the chassis through the shell handle , The handle is often hot , When the water boils, it will feel good to put a thermos in it .

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Indicator circuit

The indicator light may generally be a neon bulb lamp , Connected in series to a resistor （ The resistor is sealed in a heat shrinkable tube ）, Neon bulb lamps cannot be measured by a multimeter .（ It seldom breaks ）

Try pinching one end pin of neon bulb lamp with your hand , The other end pin touches the electrified soldering iron , If the neon bulb lights up slightly , The explanation is good .

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