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3

loss of ion.
Usually, food is constituted of organism (plant and animal). The organism is formed by all kinds of polar water
molecule, polar protein molecule, and all sorts of saltion. The center of gravity of the positive and negative charge
in the molecule is not coinciding. In normal condition, the molecule is in irregular order due to its thermal action,
thus the food do not appear polarity. (FIG.1-la). Under the action of outer electric field, the positive end of the
polar molecule trend to the negative electric field, the negative end of polar molecule trend to the positive electric
field, and somewhat arrange in order through the direction of the electric field (FIG.1-1c). This phenomenon
usually is called “TORQUE POLARITY”. When the outer electric field apply for the opposite polarity, the polar
molecule then arrange an opposite direction order accordingly (FIG.1-1b). If the direction of the outer electric field
changed repeatedly, the polar molecule would repeatedly sway accordingly. During the swaying, it is
understanding that the polar molecule would produce heat due to somewhat similar friction among them. When
the electric field is applied for ultrahigh frequent microwave field from the outside, its direction would change tens
billion times per second, so do the molecule. This kind of molecule swaying producing similar frictional heat from
the interference and block of the action strength among the molecule, and changed to microscopic microwave
heating. Microwave heating not only concerned the nature of the matter itself, but also closely connected with the
electric strength and frequency. When the frequency is low, the molecule swaying rate and the acute degree of
the mutual friction among the molecule is low, and would produce much heat. When the frequency is too high, as
the swing of the polar molecule is with rotating inertia, it made the swing do not in line with the changing rhythm
of the electric field because of the friction drag, thus, actually lowed the polar molecule swaying speed. The
friction dragging degree is concerning about the magnelectric wave frequency, polar molecule shape, and the
matter’s sticky degree. To different matter’s molecule, there is different special frequency zone. Those absorbing
microwave energy from this zone are most capable to turn microwave energy to heat energy.

Apart from the above said action, there is another action which is electric ion under the action of microwave field,
act fiercely accompanied with the acceleration of electric field. The positive ion transfer to the negative polarity of
the field while the negative ion does opposite. Accompanying with the changing electric field, the electric ion
hanging accordingly. During the transferring, heat produced with the crash among the ion. This kind of action
takes the main effect to those microwaves heating of high salt molecule.
No matter it is the polar molecule swaying or the ion transferring, they both are turning the microwave energy
which the heating matter got from the microwave field to heat energy. From the analysis of theory, we can draw
such a conclusion that the power which a unit of volume matter absorbed from the microwave field as the
following formula:
Pa=KE fErtg

δ

Pa Stands for the power the heated matter adsorbed from the microwave field.
K Stands for a constant
E Stands for the microwave frequency.
f Stands for the microwave frequency.
tg

δ

 Stands for loss angle tangent of the heated matter.

Er Stands for relative dielectric constant of the heated matter.

Fig.1-1 

(a)

(b)

(c)

Содержание EM-G2053

Страница 1: ...Microwave Oven Range E EM M S S1 10 05 53 3 EM G2053 EM S1063 EM G2063 EM S1553 E EM M G G2 25 55 53 3 EM S1563 EM G2563 EM S3553 EM G4753 Service Manual ...

Страница 2: ...LE OF MICROWAVE 2 THE STRUCTURE AND WORKING PRINCIPLE OF MICROWWAVE OVEN 4 2 1 HIGH VOLTAGE RECTIFYING CIRCUIT 4 2 2 MICROWAVE GENERATER 4 2 3 COOLING SYSTEM 5 2 4 ELECTRIC CONTROL SYSTEM 5 3 TYPICAL CIRCUIT ANALYASIS OF MICROWAVE OVEN 8 4 HOW TO ASSEMBLE AND DISASSEMBLE MICROWAVE OVEN COMPONENTS 9 4 1 THE CABINET 9 THE DOOR COMBINATION 9 4 3 THE CONTROL PANEL AND THE DOOR RELEASE MECHANISM 10 4 4...

Страница 3: ...microwave leakage check to verify compliance with the Federal performance standard should be performed on each oven prior to release to the owner F Operate the oven from a properly grounded AC outlet capable of supplying 230 volts THIS MANUAL AS WELL AS THE INFORMATION CONTAINED IN IT IS TO BE USED ONLY BY AN AUTHORIZED SERVICE TECHNICIAN FAMILIAR WITH AND KNOWLEDGEABLE OF PROPER SAFETY AND SERVIC...

Страница 4: ... and the acute degree of the mutual friction among the molecule is low and would produce much heat When the frequency is too high as the swing of the polar molecule is with rotating inertia it made the swing do not in line with the changing rhythm of the electric field because of the friction drag thus actually lowed the polar molecule swaying speed The friction dragging degree is concerning about...

Страница 5: ... YI IN NG G C CI IR RC CU UI IT T At present home use microwave oven adopt this high voltage rectifying circuit as shown at diagram 2 2 The circuit is a single phase semi wave double voltage rectifying circuit The circuit has only a high voltage capacitor a high voltage diode a magnetic leakage transformer besides the magnetron is very simple The working principle of the circuit 230V power boosted...

Страница 6: ...ode temperature rise due to anode loss caused by the electronics strike the oven surface and the heat radiate of the cathode To prevent the anode temperature rise too high thus affect the working steady and its life span it is necessary to cool the magnetron According to the different models and rate output of the magnetron compelling wind cooling and flowing water cooling can be adopted Usually t...

Страница 7: ...ld cut off the gear switch s4 to step the oven working The gear switch S5 is designed for controlling the output of the microwave oven actually for controlling the output of the magnetron It mainly by the method which make the magnetron working internally at the same working point to change the output of the magnetron This method was called CONDUCTION RATIO CONTROL But there is another method whic...

Страница 8: ...t damp heat acid and alkali it should also comply with the food health requirements To improve the heating evenness there often fixed a turntable glass tray at the bottom of the cavity FIG 2 8 It is through changing the relative place of the microwave and the heating matter to improve the heating evenness The turntable tray is usually made of heat resistant glass the glass contains some dielectric...

Страница 9: ...ve the food around and making the food heated evenly The microcomputer begins reckon the time when it reached the sets time power relay are cut off the power of the lamp all the motor and the magnetron are cut off the food heating process ended During the heating if the door was opened the interlock S1 S2 will cut off S3 will close all the motors and the magnetron will also be cut off the lamp wil...

Страница 10: ...he up right and left troughs have been inserted with the curved with the curved rim of the oven FIG 4 1 b If the cabinet and the oven are not tallied exactly then it should be reassembled or those untallied parts should be smoothed 3 Tighten those four screws please make sure that one of the screws should have a plum blossom shape washer to keep a good earth 4 4 2 2 T TH HE E D DO OO OR R C CO OM ...

Страница 11: ... After assembled check whether the door hook is working in normal 3 Tear off the back protective paper of the window then the sides of adhesive tape as FIG 4 1 and stick it on the window Tear three right sides protective paper about 10mm and fix the window in the doorframe as FIG 4 1 4 Tear off the adhesive protective paper of the lining and stick it on the door as FIG 4 1 slip the hook on the doo...

Страница 12: ...aced well It should not be fixed if there is no copper filament weaved washer for it may cause the magnetron and the oven can t earth well and cause large amount of microwave leakage Attention When a new oven matches a magnetron the meatl lustre at mark should be polished with a sand paper FIG 4 7 2 Aim the head of the magnetron antenna to the hole of the wave guide housing tighten the four screws...

Страница 13: ...s part To disassemble 1 Pull out the two terminal of the fan motor FIG 4 11 2 According to the FIG 4 12 pull out the lead plug which marked A and C from the thermal cutout and the fuse housing separately and take off the earthing screw which marked B FIG 4 12 3 Take out the power supply cord from the trough as the figure shows 4 Loosen the screws shown on the FIG 4 13 with a screwdriver and take o...

Страница 14: ... 8 8 T TH HE E D DI IO OD DE E Firstly do as the 1 2 3 steps of of this part To disassemble 1 Pull out the diode plug which plugged in the capacitor 2 Loosen the screw which fixed the diode and take the diode off To assemble 1 Insert one end of the diode to one feet of the capacitor s connect piece 2 Fix the diode with one screw pay attention to the polarity of the diode refer to FIG 4 16 4 4 9 9 ...

Страница 15: ...h connecting lever arm and the working lever from the holder Assembling steps 1 Slip on the connecting lever arm and the working lever into the switch holder 2 Assemble the interlock switch and pilot switch to the switch holder make sure they are assembled correctly 3 Tightly fix the holder with two screws 4 Check the position of the hook and the switch holder Close the door push and pull the low ...

Страница 16: ...paper on the back and stick it on the plastic board smoothly 3 Tear off the protective paper of the light touch switch 2 and stick the switch on the back of the plastic board smoothly 4 Assemble in the PC frame and PC board as FIG 4 22 and fix them with three screwes 5 Fix the range wires as FIG 4 24 the means are Insert the range wires first make sure that its notch is tallied with the flange of ...

Страница 17: ...operating condition but the power plug haven t been plugged in measure the two feet L N of the power plug with R 1 grade of an avometer the resistance value should be about 2 5 ohm If open circuit occurs then you must check whether the 8A fuse is broken the primary winding of the transformer is open circuit the thermal cutout is open circuit or not you must check whether the interlock device is pu...

Страница 18: ...K grade of an avometer the rod end of the avometer connect the cathode of the diode the rod end of the avometer connect the anode of the diode FIG 5 7 The avometer reading should be about 150 thousand ohms The change the rod to different electrode the reading should be If the reading is very small and near to short circuit it indicates the high voltage diode has been punctured and should be replac...

Страница 19: ... the capacitor is normal Then check the earth of the magnetron s two filaments to see whether they are short circuited FIG 5 13 If they are short circuited and the filament strikes the shell of the magnetron it indicates the magnetron has broken and should be replaced by a new same model one If the magnetron is also normal then test the pilot switch Pull out the two plugs of the switch Measure it ...

Страница 20: ...in If the leakage still exceeds standard requirement then inspect whether the right oven is even or not if not smooth it Then adjust the door and the oven to eliminate their loose to the ultimate If there still exist microwave leakage measure near the magnetron with the probe of the microwave leakage mea sure If the leakage is larger the oven should be turned off and check whether the four screws ...

Страница 21: ... I IN NS SU UL LA AT TI IO ON N Before conducted measure the insulation resistance among those electric metal parts and the nonelectric metal cabinet with a 500V D C Megaohmmeter The resistance value should not be less then 2 megaohm Testing condition Door closed power at high time set at 3 minutes This is the operating condition of the oven but the power plug is not connected 5 5 4 4 2 2 M MI IC ...

Страница 22: ... interlock switches use your ommeter digital or analog type to check the electrical continuity 2 Make sure the power cord is pulled out and the high voltage capacitor is discharged before the electrical continuity check 3 Set the ohmmeter to Low Resistance range and connect both leads alligator clips to the switch terminals 4 Open the door and notice the meter reading the primary or secondary inte...

Страница 23: ...from the fourth minutes The winding of the fan motor in open circuited The fan falls off The plug of the fan motor falls off The turnatable shaft is griped with the mo tor bearin The cooling vent blocked 1 Change the fan motor 2 Change the fan 3 Insert the plug 4 Overhauling them 5 Repairing it 6 When starting the oven it can t heat and with wenwen noise The high voltage diode was punctured Change...

Страница 24: ...ts Attachment Æ EM S1053 explore view and parts list Æ EM G2053 explore view and parts list Æ EM S1553 explore view and parts list Æ EM G2553 explore view and parts list Æ EM S1063 explore view and parts list Æ EM G2063 explore view and parts list Æ EM S1563 explore view and parts list Æ EM G2563 explore view and parts list Æ EM S3553 explore view and parts list Æ EM G4753 explore view and parts l...

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