Friday, March 22, 2019

Blames In The High Voltage diode

Blames In The High Voltage diode(صيانة دايو)

The high voltage or high voltage diode (figure 9) is one of the segments that causes the most issues in the task of a heater.

The transformer creates 2000V that achieve the capacitor, the other terminal of said capacitor is associated with the diode that sends the current to ground as heartbeats. The capacitor plays out the capacity of voltage multiplier, achieving the 4000V that feed the microwave to create the microwaves.

This diode can not be estimated as a great diode, since the measure it generally gives is Infinite in any capacity that is estimated.

The great path is to have a high voltage generator, place the diode and check that at the contrary end a "circular segment" is produced when it is drawn closer to the generator's chassis or ground. Another approach to quantify the diode is to apply a high DC voltage and measure the voltage drop in said diode.

To do this, we put in arrangement with the diode an opposition of 1kohm and apply a voltage of about 30V to the set.

With the diode in great condition, in direct polarization, we will have a voltage drop in it of 5 to 7V, with switch polarization, the diode won't lead current so we will have in it, the source voltage of 30V.


The capacitor or capacitor can be tried similarly as an ordinary capacitor, its esteem is usually somewhere in the range of 0.9µF and 1µF with a working voltage of 2100V .

The basic measurements that we can perform, being increasingly prudent a needle polymerometer, are:

Measure between terminals, you should give intermin ability .

Measure between every terminal and mass, is performed in the size of MW must give similarly interminable. Despite the fact that these measurements are not conclusive, since they are not performed under pressure.


A thermistor is a part that changes opposition with temperature, in this manner, the best approach to quantify the thermistor, considering that it isn't in excess of a temperature switch, is the accompanying: when it is in great condition, it must give congruity, between terminals , if there should be an occurrence of being in poor condition, give boundless obstruction measurement or a few hundred ohms.

Between the terminals and the front plate must give unendingness.


The transformer comprises of 3 windings, which must be estimated while being disengaged from the equipment.

Essential winding of 110V/220V. It has two contacts and is the winding of thick copper wire, it must gauge somewhere in the range of 1ohm and 3ohm
Optional winding of 2000V. It has one yield contact and the opposite end connected to the transformer chassis. It is the winding of fine copper wire and its obstruction extends somewhere in the range of 80ohm and 120ohm. Forces the capacitor through thick link.

Optional winding of 4000V.

It usually comprises of 2 long yield links, with male connectors secured at the finishes.

It is a winding of few turns that is located in the focal point of the transformer, from one perspective it is associated legitimately to the microwave and on the other, to the terminal of the condenser and to the diode that infers to ground. With the analyzer we should gauge somewhere in the range of 0ohm and 1ohm. See figure 14.


In the financial heaters there are no microcontrolled plates , we just discover the power selector and the clock, which can frame a joint square, by methods for certain riggings that go along with them.

The clock is a part of mechanical kind, in which we can choose the initiation time of a contact, between 10 sec and 45 minutes around. This part changes as indicated by the producer and model. For instance, a Samsung 331 has a system of riggings and cams, with an engine of 20V sometimes, that when actuated by a similar contact of the clock, starts to turn, it additionally has a ringer that is initiated by a cam, toward the finish of the planning.


Again we need to state that this stage shifts a ton in its development relying upon the brand and model of the stove. For an affordable Samsung, this control is connected by riggings to the clock and depends legitimately on it, it comprises of a voltage step transfer. It is in charge of providing 110V/220V advance to the essential of the transformer, with a period that relies upon the selected power and the pivot of the clock gears.

The contacts are usually from 10A to 15A by 110V/220V yield contact and a loop in the request of 100ohm (Figure 16).

The most effective method to CHECK THE CONTROL SYSTEM

The to some degree progressively expound ovens, rather than having the control of intensity and time depicted, has a microcontroller as a component of a control framework. This control module, which is in charge of playing out the diverse elements of the stove consequently,

can have a few disappointments, due to the transfers and electronic segments, there might be disappointments in any of the working voltages, nitty gritty beneath. The framework likewise has the presentation and the console. Said console can have issues of short in some key, outstanding this one squeezed and obstructing the equipment. Ordinarily, the control module or framework works with 3 unique voltages,

5 Vdc for the power supply of computerized circuits.

20Vdc for the excitation of the showcase.

3Vac for the showcase fibers.

In Figure 18 we can see a square outline of the control arrangement of a run of the mill microwave with the conceivable flaws that can happen in the distinctive stages.

The trial of the microcontroller comprises of verifying the voltages and the nearness of flag in some test point given by the maker. To check this part you should have the information sheet of the coordinated circuit.

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