Sometimes when the microwave oven is in operation, excessive noise is heard, the case warms up and the smell of burning is heard from it. In this case, there is a high probability that there are certain problems with the voltage converter. And in order to be convinced of this, it is necessary to identify its serviceability.
How to check the transformer of a microwave oven for serviceability
The health of the converter is checked by determining the voltage on the windings. But with parts in which there is a large voltage, this method is unacceptable. The thing is that on the secondary coil, the voltage reaches a dangerous 2 kV. That is why the manufacturers of this equipment are advised to check the integrity of the converter by measuring the resistance of the inductor.
Its integrity can be determined in another way. The bottom line is that check current at idle. To do this, disconnect the wires that are suitable for the device, and remove it from the housing. In parallel with this, an ammeter is installed on the first coil. Through it serves food.
Important!If the converter is corrected, the following data will be displayed on the tester indicator, the current in the idle mode will be in the range from 0.3 to 0.5 A. If the numbers are higher, then most likely the transformer is faulty.
Check the transformer yourself
There are two ways to identify its performance: safe and energized. About it below.
Safe diagnostics: how to check the microwave transformer with a multimeter
Safe research is performed using a tester (multimeter). The essence of the study is the search for any problems. The sequence of actions is as follows:
- The device is set up for the measurement, setting the required measurement limits.
- After that, check the resistance of the coils - primary and secondary.
Important!Before taking measurements, the transmitter must be removed from the housing.
If the number “1” appears on the tester panel, a break has occurred. If there is a closed circuit on the first coil on the indicator should be a value of the order of 4 - 4.5 Ohms, on the filament coil 3.5-8 Ohms, on the high-voltage 140-350 Ohms. The multimeter is set to a measurement range within 200 ohms. When conducting measurements, the results should not go beyond the limits shown.
Important!If the measurements went beyond the specified limits, then, most likely, a short circuit between the turns of the winding occurred.
It is advisable to take into account the error of the measuring device. In order to check the status of the device, there is no need to return the furnace to a service center. If the user has knowledge of the basics of electrical engineering, then he will be able to test the voltage parameters.
Live test
If a short circuit test is performed, but the product still does not work as usual, then it makes sense to determine the state of the secondary throttle.
Attention! This is a dangerous process, and when performing work, safety measures must be observed.
Algorithm for checking a device under current as follows:
- 220 V is supplied to the product.
- Using a device that allows work from 2 kV, check the voltage at the outputs of the windings.
The voltage on the glowing coil should lie within 3 kV, on the high-voltage - 2 kV.
Reverse check
This method of testing a transformer is probably the easiest. 220 V is supplied to the secondary winding, 24 V will be taken from the primary. In the event that 12 V is applied to the primary winding, it will reach 109 V.
If the device is heating in idle mode, then most likely a short circuit between the turns of the winding. If it heats up during operation, and when it turns off, it stops heating up, then you need to look for problems further.
Precautions during the operation of the microwave transformer
When taking measurements, you can get an electric shock. Moreover, its consequences are unpredictable. By following simple rules you can avoid this kind of trouble:
- When determining data on a working furnace, it is inadmissible to touch parts installed in the furnace.
- To take measurements on the tester, install the so-called clips - crocodiles and connect to the chains with their help.
If it becomes necessary to touch the parts, perform the following manipulations, which will avoid shock from the capacitor:
- disconnect the product from the network;
- bend the magnetron leads to the furnace body.
In the standard microwave oven circuit, a resistor is provided that takes on the discharge of the capacitance, but it cannot completely eliminate the danger of electric shock. The resistor may burn out. In this case, an electric shock can be fatal. Be careful!
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