电磁炉维修技术(Maintenance technology of induction cooker)

电磁炉维修技术（Maintenance technology of induction cooker）Maintenance technology of household induction cooker
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Update: 2013-07-13, 10:15
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Working principle of electromagnetic oven
The electromagnetic oven is mainly using the principle of electromagnetic induction to convert electrical energy into heat energy of kitchen appliances, when the electromagnetic oven in the normal task, by the rectifier circuit to communicate 50Hz voltage into DC voltage, and then after the control circuit converts the DC voltage into high frequency voltage 20-40KHz, induction coils will occur in alternating magnetic field the bottom of the pot with repeated change, the pot bottom ring current (Wo Liu), short circuit thermal effect and the use of small resistance and large current occurrence of heat directly to the bottom and then quick heating, heating appliances in something. The heating method of vibration heat generation can reduce the intermediate part of heat transfer, and greatly increase the heating power
Tools / raw materials
Electromagnetic oven, screwdriver
Methods / steps
One
The boot after the active reset buzzer ringing
Defect analysis:
Presents this kind of trouble, mainly is the pot temperature examination circuit or the main control IC question, below introduces its repair method.
View the pace:
The pot out of the thermistor insert plate, using a multimeter to measure the resistance, resistance of the thermistor at room temperature is 100K. Because the European thermistor is selected as negative temperature coefficient, the resistance will follow the increase of temperature drop. If the measured value in the measurement for 0 euro or resistance infinity, indicating the thermistor circuit breaker may have, the thermistor is removed and the new change of the same type thermistor. The electric machine test all normal, troubleshooting.
If in the last step, the problem has not been eliminated, it is necessary to power on the circuit analysis. Using a multimeter to measure the main IC 16 voltage, 17 feet (16 feet
4.95V, 17 feet of 0.42V), if the voltage measurement to the normal, but with no cleaning, we can put the wrong lock in the main control IC, the master IC removed from the board, for the same type IC, master of the same standard, power on test machine, everything is normal, troubleshooting.
If the voltage in the previous step to measure is not normal, we can use a multimeter to measure resistance grade R29, R28, R35, C19, C17 can damage the components damage removed, replaced with the type of element equipment, electrical test machine, all the normal faults can be eliminated.
If the measurement of the above yuan equipment is no shortage, and the problem has not been eliminated, we can also fix the problem in the main IC, replace the new IC, the problem can be eliminated.
Two
Electric buzzer ringing
Defect analysis:
Present this problem, mainly IGBT temperature detection circuit, zero detection circuit or main control IC problems, the following describes its repair methods.
Fault discrimination:
In order to find the fault point quickly, we only need to measure the voltage of the following points, so that we can judge the
position of the defect. The following is the correct value of the voltage of each point. IGBT temperature detection circuit --- the main IC-18 foot - voltage value: 2.79V, zero crossing detection circuit - - the main IC-22 pin - voltage value: 2.39V
(1) faults of IGBT temperature detecting circuit;
View the pace:
IGBT temperature fuse plug out from the board, with multimeter to measure its resistance value, at room temperature, fuse resistance value of 0. When the temperature is above 85 degrees, the temperature fuse will break and form an open circuit. In the measurement, if the resistance can not be measured, it indicates that the temperature fuse has been broken, the temperature fuse is removed and replaced with a new type of temperature fuse.
If in the above step, the problem has not been eliminated, we must power on the circuit analysis. Measurement of IC2 (DM7406N) 6 foot voltage can be high (voltage value of 2.77V), if it is high, and the problem is not removed, it indicates that IC1 has been damaged, replacement defects can be removed. If the measured voltage is low, then the reason for the fault there are 2 possibilities, one is IC1 bad, and the other is IC2 (DM7406N) bad. In this case, we can only solve the problem by sweeping. First change IC2, if the replacement after troubleshooting, it means that IC2 has been bad, if the replacement after the problem still exists, it indicates that IC1 has been damaged, replacement defects can be removed.
If the voltage step to measure the normal, see R30, R31, R32, C18 with a multimeter can damage the components damage removed, replaced with a new element of the same type equipment, electric machine test all normal, troubleshooting
Three
Fault of zero crossing detection circuit
View the pace:
First measure the main IC of the 22 feet, whether there is 2.39V voltage, if the voltage is normal, and the problem is not removed, it means that the main IC has been damaged, replacement defects can be removed.
If the voltage measured is abnormal, please check R36, C24, C23, D10,
D11 can have a problem, the problem of the replacement of components, fault can be eliminated, if the yuan above equipment is no problem, but the problem has not eliminated, we can conclude that IC is bad, replace the new IC, power on test machine, troubleshooting.
Four
Breakdown of low voltage power supply
View the pace:
There is no 5V power output. 7805 if there is power on measuring the input voltage of 12V. If there is no 12V input and 5V output voltage, please check whether the normal C34, R56 may be disconnected after 5V level power supply circuit, if the above components are normal and short circuit power supply level, indicating the 7805 have been bad, after the replacement problem can be eliminated. If there is no voltage input for 7805, then we can measure the secondary voltage of the transformer. If not, it indicates that the transformer is out of order and that it can be removed after replacing it with a new transformer. If the transformer has a voltage output, and the D201 has no voltage output, it indicates that the D5 has been broken and that the defects can be removed after replacement.
No 12V, 10V power output. If there is no 10V power output, let's check the Q1 on the power output voltage can be 12V, if not, let us test again D6 can have 25V voltage output, if there is, please check C31, C32, C30, C29, C28, R39, Q1. Replace defective equipment with problems that can be swept away. If the D6 does not have voltage output, let us measure the transformer again whether or not there is a voltage output. If not, it will indicate that the transformer has been damaged and that the defects can be removed after replacement. If the transformer has a voltage output, it indicates that the D6 has been broken, replaced with the new D6, and the problems can be eliminated.
There is no 19.4V power output. Power up the D7 to see if there is a 27V voltage output. If yes, please check C27, C26, C25, D7, Z2, Q3. Replace defective equipment with problems that can be swept away. D7 if there is no voltage output, then we measured whether the transformer can output voltage, if no transformer
is bad, if there is, it indicated that D7 had put more than $circuit equipment damage after the substitution problem can be eliminated.
Five
Power circuit fault
View the pace:
First, the problems of parts and components are checked, and the damage of EMC protection module, transformer, filter capacitor, fuse tube and power cord can be detected. The damaged parts can be replaced and eliminated.
If the above step did not find the problem, then we will power on the circuit detection (focus on high voltage power supply), the primary view there is no 220V communication power input, and then check whether the transformer primary voltage input 220V communication, if there is no normal input voltage and transformer secondary voltage output, indicating the transformer has been damaged, transformer replace with standard, troubleshooting.
If the above-mentioned high-voltage power circuit is no problem. Still can not boot, it indicates that the fault in the
low-voltage power circuit. The low-voltage power circuit we refer to here refers to the 5V power circuit. Please refer to the detailed troubleshooting procedures for low voltage power supply.
Six
Fire pipe
Fault analysis: the common problems with the present together damage to other components, such as IGBT, rectifier with breakdown, a new insurance tube, do not immediately on the electric machine, or may cause the fuse tube again.
View the pace:
A universal table view IGBT, rectifier can breakdown, the damaged components removed, replaced components of the same type. Then use the universal table to check the resistance R310, R311, measuring the two yuan equipment, must be removed to carry out the accuracy of the measurement, the damaged yuan equipment replacement. You can't connect the coil to the coil at the following pace
In this step, the following materials should be prepared: thin wire, one wire, and 5.1K resistor. Connect the 24 foot of the main IC with the IC3 9 foot of the LM339, and use the 5.1K resistor to connect the IC3 8 foot of the LM339 and the negative pole, and remove the R9. The end of the above step, the electric coil in the boot disk case, 7 pin voltage with a multimeter measuring IC5 - TA8316AS, if the voltage measurement to 1.07V, indicating the synchronous vibration, drive circuit can work properly. Disconnect the power supply, remove the 5.1K resistor, wire, wire, and install the R9, then refer to the current sensing circuit for inspection. After completion of the above step, the electric test machine is normal on the coil coil, and
the trouble is removed.
Third, if measured to the IC5 seventh feet voltage is not normal, then we measure IC5's 1 foot voltage can be 0.73V, if the voltage is normal, will indicate IC5 - TA8316AS has damaged, replace the problem can be eliminated. If the voltage on the 1 pin of IC5 is abnormal, please check the synchronous circuit. Please refer to the troubleshooting process of the synchronous circuit for more details. If the synchronous circuit is no problem, then we have to go to the vibration circuit to see, first check R11, R12, R5, R15, R13, R14, D4, D1, D3, D2, C6, whether there is damage, damage to the replacement of equipment.
(to clarify here): in the electromagnetic oven can be normal tasks, must not be multimeter to vibration circuit voltage measurement. As the multimeter itself has certain disturbances, it is very simple to disturb the vibration circuit, and then the IGBT will be burned in the case of asynchrony. In the end of the above task, and then measure the IC3 5 foot voltage can be 12V, if the voltage is not normal, please check the IGBT high voltage maintenance circuit, in detail, please refer to - IGBT high maintenance troubleshooting process. At the end of the above step, check the IC5's 7 foot voltage in accordance with the above method. If the voltage is normal, indicate that the trouble has been removed.
Seven
Fan does not rotate
View the pace:
In some conditions, the fan fan removed, replaced with a good standard, if the wind power is turned on, function of the normal starting operation, it is to clarify the wind turbine itself has a problem, replace the fan after cleaning can be wrong.
If the fan itself is good, it is necessary to power on the circuit board for live inspection, the first measurement of the fan can have 12V task voltage, if not, please look at the power circuit. If there is 12V, now we have to consider the main control IC has no base of high level output to Q2, voltage of 25 foot measurement is mainly IC, if the measurement value is 0V, indicating the main IC once damaged, replace the same type of IC, can eliminate problems.
If the measured voltage to 25 feet of the primary IC is in high level, but with no cleaning, we must be on the fan drive circuit element equipment check, measure of Q2, D8, R41 using the multimeter, find out the damaged elements, bad component replacement, replaced with new material. The electric machine is normal, troubleshooting.
Eight
Unheated
Defect analysis:
The circuit of the fault is more than that of the synchronous circuit, the circuit for detecting the cooker, the IGBT high temperature maintenance circuit, the IGBT high voltage
maintenance circuit and the current detection circuit.
(I) faults in synchronous circuits
View the pace:
In no case of standby wiring ring disc, voltage measurement multimeter IC3--LM339 eighth feet can have 7V, 14 feet can output a low level (static electric here 0.21V), if the voltage measurement to the high level, indicating the IC3-LM339 was damaged, compared with the standard for the same type. On the electric machine is normal, can eliminate problems.
If the voltage step to measure the normal, please use the universal table view R301, R302, R307, R306, R303, R10, Z301, C5 can damage the components damage removed, replaced with a new element of the same type equipment, electrical test machine, troubleshooting.
(two) fault of drive circuit;
(the circle can not wiring this step, otherwise will cause burning IGBT) let's IC3 pin 5 connected to the 5V power supply, the 4 foot connected to the anode, coil down, power driver circuit for voltage analysis, using the multimeter to measure IC5 (TA8316AS) second feet can have 18V if not, please check the power supply, the power supply circuit. If there is at the moment, press the power button on the measurement of IC5 (TA8316AS) first feet, whether there is a 7.77V input voltage, output voltage of seventh feet can have 17V, if the normal input voltage, the output voltage is not normal, it indicated that
IC5 (TA8316AS) has been damaged and replaced after the test machine is normal, can eliminate problems.
If the voltage step to measure the normal, see R24, R25, R23, R22, R21, R20, C8 and the existing problems of the element analysis equipment down, put the same type of element on the electrical equipment, the test machine is normal, can eliminate problems.
(three) examination of the circuit of the cooker;
View the pace:
First, to see whether the pot diameter and supplication together, please use MD special pot, to see whether the two terminal can be loose.
Power on standby in the case of measuring the IC4--LM393 second, third foot voltage, 2 feet can be greater than 3 feet (2 feet 7.33V, 3 feet 2.49V), if not, go to the synchronization circuit to see. If yes, measure the main control IC 20 feet can have a low level, if it is high, to clarify the IC2 is bad, replace the test machine is normal, the problem can be removed. If measured to the main IC 20 feet is low, power off, the coil plate is removed, and then measure the main IC 20 foot voltage, if for high level, and the problem is not swept, it means that the main IC is damaged. If the voltage is measured to the low level, then the problem is there are 2 possibilities, one is the main IC bad, another is IC4 bad, we can replace the IC4 LM393, if the replacement, troubleshooting, indicating the fault point in IC4, if the problem is not to replace the IC4. This marked
the fault point in the main IC, after the replacement problem can be eliminated.
(four) IGBT high temperature maintenance circuit fault;
View the pace:
First, power on, see whether the cooling fan in turn, if not turn,
After removing the fan drive circuit and the blower itself, we can conclude that the main IC has been damaged and replaced with the new standard master IC, which can be eliminated. If the wind function tasks, then we can clean up, is the main IC fault.
The 7 foot IC4--LM393 II on the electric voltage measurement, when not boot, the output is low, start at the moment, this pin will output a high level, is still low, indicating the maintenance circuit voltage, when the voltage is move, let's measure IC4 fifth feet can more than sixth feet if it is, that IC4--LM393 was damaged, replace IC4, defects can be eliminated.
If the voltage of the IC4 fifth foot is smaller than the voltage of the 6 pin, the power failure can be checked by the multimeter, whether the R54, R52, R53, R51 and Q5 can be damaged and replace the damaged equipment. Problems may be swept away.
(five) IGBT high voltage maintenance circuit fault;
Detection pace:
In case the coil is not connected, power on the IC3 comparator LM339 can be low on the first pin. If it is low, the IGBT high voltage maintenance has been indicated. Measure again the voltage of 7 feet can be 4.98V, if be, indicate IC3 - LM339 ever damaged, after replacement, the problem can be swept. If the measured voltage is abnormal, please check whether R16 and R17 are normal, replace abnormal equipment, and correct the problem.
(six) fault of current detecting circuit;
Detection pace:
10 feet on the electric voltage measurement in the stand-by condition of IC3 - LM339 can have 0.56V, if the voltage is not normal, see R33, R34, C20, C21 can be normal, if the components above normal, indicating the main IC was damaged, please replace.
Measuring the voltage of 13 feet of IC3--LM339 can be low level. If it is high, it indicates that IC3 has been damaged. After the replacement, the problem can be eliminated.
Measure 12 feet of IC2--7406 again whether can be tall, if be low level, measure 13 feet whether can be low level, if be, mark IC2 - 7406 once damaged. If the 13 foot is low, it indicates that the main IC has been damaged, replace the damaged equipment, and the problem can be eliminated.
(in this circuit, if the Q4 is always in conduction, the electromagnetic oven will not heat up). If it is always in the
cut-off state, after the induction cooker starts, the task current can not be manipulated, and when the rated current exceeds the IGBT, it will cause IGBT burning. The other test data, the electromagnetic oven Daquan can refer to the attached pages in the detection circuit fault when the grounding resistance and pin voltage to distinguish fault, test environment is not detected in a coil disk case.。