Checking the microwave transformer for serviceability

Microwave ovens use microwave radiation to heat products, so this transformer is considered one of the most important elements in the radiation generation circuit. This is the part that must properly use the mains voltage, and harmoniously convert it into the values ​​necessary for the normal operation of the magnetron device, all this happens through the primary winding.

Microwave transformer

High voltage transformer in the electric circuit of the furnace

The described device contains in its structure a frame, a magnetic wire, a primary winding in one quantity, and a secondary winding in an amount of two. The secondary type winding is necessary for transmission to the magnetron circuit, in particular to the anode line and the filament, power. An incandescent thread always contains a thicker wire, because a voltage passes through it, which gives almost three volts at the output - this is a high-voltage wire. The anode line, windings of the secondary type, involves the generation of voltage of an alternating direction, the maximum of which is 4 kV. The primary winding is always powered by a household electrical network, therefore it works in standard household indicators of 220 volts.

The structure of the microwave transformer

Sometimes there is a difficulty with the designs of various brands of furnaces, because a different manufacturer offers the consumer goods of different types, sizes or variations of fasteners. The power class, the degree of voltage of the output direction in the secondary type winding may also differ. Often the thickness and resistance of the wire is different, so the amount of material varies.

It is important to remember that at one output of the magnetron there will be a circuit with the winding of the secondary sample, as it always closes on the case.

What is contained in the microwave and its circuit in addition to the transformer:

• high voltage diode and capacitor;
• end circuit breakers;
• fused magnetron;
• unit for controlling the heating process;
• platform motors, due to which there is a circular motion when the program starts and a fan.

Ovens of more expensive production lines offer users pulse units instead of a transformer. They are characterized by low weight, but have a more complex design device.

Pulse Assignment Block

Possible transformer malfunctions and their symptoms

It should be remembered that without special need there is no need to diagnose the equipment, it should be consulted only in two cases - when the household appliance began to work not so efficiently, excess noise appeared or it does not respond at all to start-up in a state included in the power consumption network.

What symptoms will be observed in case of failure of the transforming unit:

• After selecting a program and pressing the start button, the oven buzzes or makes noise, which was unusual for her earlier.
• Food is not heated evenly or has not reached the required temperature at all.
• You smell the characteristic burning smell of an insulating winding.

If you notice the above symptoms, more use of the stove is not recommended. Quickly disconnect the device from the power supply, because otherwise, the consequences can be disastrous.

Often, breakdowns can occur due to the uneven abrupt current flow into the household electrical network. This reason can never be denied or foreseen, so you should tune in to carry out repair work. In addition, during this process, you will be able to notice a defect in your device that was approved during production.

Possible symptoms may be identified due to a list of reasons:

• Frequent cases are rupture of the wires of the secondary or primary winding of the wire, there are options when both windings are damaged at the same time, but this case is quite rare.
• Short circuit or in a circuit on the line between the output of one winding and the input to another, and possibly simultaneously closed both windings.
• The magnetron could give an open or short in the filament circuit.

The magnetic wire is a transformer block, which is composed of electrical steel sheets. Deviation of these electrical sheets can cause alien extra noise during the start of the program, if this is the reason, then you will have to completely replace the transformer. The user perceives and calculates this malfunction even visually, and in percentage terms, breakdown of this type is very rare.

Microwave transformer

Safe Checking Procedure: How to Safely Test the Microwave Transformer

A do-it-yourself check implies the presence of a certain amount of necessary auxiliary equipment, the first thing you need is a multimeter, if not, then get a bipolar indicator, which has built-in power sources.

In addition, you will need different types of screwdrivers, pliers and an ohmmeter.

Summarize the basic scheme for safe verification of a technical device:

• We make sure that the device is disconnected from the general household power consumption network.
• We get rid of the casing by screw twisting.
• We make sure that the capacitor is not energized and is completely discharged.
• We remove the terminals as accurately as possible from the transformer block.
• We study the state of operability of its windings. At this stage, we must understand whether this is the cause of the breakdown or malfunction. If everything looks in order, then install everything in its place in the reverse order and look for other causes of the problem.
• If, while studying and examining the appearance of the windings, you noticed symptoms of shorting or breaks, then this is the reason for the failure, so you need to fix the problem, namely, replace this device with a working one.
• After carrying out the replacement manipulation algorithm, the device is assembled in the reverse order and the degree of its operability is tested.

In the case when all the procedures for replacing the defective part were completed, and the furnace did not work when it was turned on, it is necessary to try to diagnose it by connecting to the mains, or look for other reasons.

As soon as you removed the transforming unit and saw insulating fusion on the winding, and in addition to everything, it exudes a corresponding smell, then it makes no sense to conduct testing on such a part. Exclusively a replacement device is necessary in this embodiment.

How to diagnose a transformer:

• We connect the multimeter to the mains to start the heating program. A transforming device must be completely de-energized. To make sure that electricity is not supplied to it, use a multimeter.
• With a multimeter, we check the connecting points of the primary winding, from which the power comes from the household power supply.
• Be sure to monitor safety and work carefully and carefully, sudden movements or careless behavior can cause electric shock.

Dismantling the device with subsequent verification is considered safe only when the household appliance is not fed from the household power supply.

A microwave oven contains a capacitor that is capable of storing and storing a certain amount of electricity for a long time.

Capacitor

Therefore, it must be discharged before the necessary diagnostics. Most often they use a closure for this, in which case it is necessary to close its contacts, between each other, or bring it to the case when the voltage is working. To carry out this manipulation is using pliers or pliers.

Methods for diagnosing device health

After conducting independent resolutions of all malfunctions, taking into account all safety rules and standards, the microwave oven must be assembled in the reverse order, as indicated in the diagram above, and included in the household standard electrical network. Use new parts that will work properly after the replacement.

Safe Verification Method

To describe one of the safest methods, you need a multimeter.

Multimeter

With it, we check whether the whole windings on the transformer are checked. To conduct a safe diagnostic method, perform the following steps:

• We set the necessary resistance indicators on the measuring device, both secondary and primary, including.
• We produce the same with a transformer, which has already been disconnected and dismantled.
• The multimeter display will show a unit if there is a breakdown in these places.
• When the circuit is closed, the provided indicators of the filament winding will be in the range of 3.5 - 8 Ohms, the primary winding will show from 2 to 4.5, the secondary winding of the high voltage level will increase to the limits from 140 to 350 Ohms.
• If the device shows parameters below or above the specified limits, then there are problems in the circuit between the turns.

Be sure to consider the error parameters of the measuring device when taking measurements. Close the probes of the device in the limit in which you use it. This action will indicate the true error parameters.

Even if you have the necessary instruments and devices for independent diagnostics, but you have absolutely no experience in matters related to current, you should turn to professionals in your field and not experiment, because this can cause many injuries.

Live test

You made a resistance measurement algorithm, all the indicators were within the above standards, and the error of the measuring device was taken into account, but the furnace still does not work, you should pay attention to the performance characteristics of the operation.

Microwave repair

Checking the voltage indicators of the output type is considered a rather dangerous way of testing the windings of a secondary nature. How to make this measurement correctly:

• The appliance is connected to the mains.
• Using a tester, test the readings of each winding circuit at the output level. The channel value should not exceed 3 V, high-voltage indicators should be no more than 2 kV.

Everyone has the right to decide for himself in what way it is easier and better for him to use, the main thing is that he would be safe. Sometimes it’s enough just to ring the contacts and understand what happened and what causes the breakdown.

Microwave will last a long time with proper care