Will the breakdown of the thyristor on the inverter circuit board burn other components at the same

There are three main reasons for the breakdown of thyristors:

1. Overvoltage breakdown:

Overvoltage breakdown is one of the main reasons for the breakdown of the thyristor, the ability of the thyristor to withstand the overvoltage is almost timeless, even in a short period of milliseconds overvoltage will be broken down, so in the practical application circuit, the RC absorption loop must be connected to both ends of the controllable silicon to avoid the instantaneous overvoltage caused by various irregular interference pulses. If thyristor breakdown occurs frequently, check whether the components of the absorption circuit have burned out or failed.

2. Overcurrent and overheat breakdown

In fact, overcurrent breakdown and overheat breakdown are the same thing. Overcurrent breakdown is when the current passes through the thyristor chip to produce a thermal effect inside the chip, causing the chip temperature to rise, and when the chip temperature reaches 175, the chip will fail and cannot be recovered. Under normal use conditions, as long as the working current does not exceed the rated current of the thyristor, this thermal breakdown will not occur, because the principle of overcurrent breakdown is caused by the increase in temperature, and the process of temperature increase takes a certain amount of time, so the overcurrent in a short period of time (hundreds of milliseconds to a few seconds) is generally not breakdown.

3. Overheat breakdown:

The thermal breakdown here refers to the thermal breakdown that occurs under the condition that the working current does not exceed the rated current of the thyristor, and the reason for this breakdown is mainly that the auxiliary heat dissipation device of the thyristor works poorly and causes the temperature of the thyristor chip to be too high and causes the breakdown. For the use of water cooling to work, the main check is whether the inlet water temperature is too high (generally the water temperature should be below 25, but the maximum can not exceed 35), whether the flow rate is sufficient; For the use of air-cooled work, should check whether the number of revolutions of the fan is normal, and the ambient temperature can not be too high, but whether it is air-cooled or water-cooled, if you only replace the chip when replacing the thyristor, pay attention to the contact surface between the chip and the radiator must ensure good contact when installing, the contact surface should be smooth, there can be no scratches or bumps and no dust trapped, but also to ensure that there is enough and uniform pressure, especially for the water-cooled thyristor, the tension of the three bolts must be uniform, And also to check and clean the scale frequently, too much scale will also affect the heat dissipation effect and lead to overheating breakdown. In addition, if the chip is replaced multiple times, it will also cause the contact surface of the radiator to deform and affect the heat dissipation effect, if one of the thyristors on your machine often breaks down and cannot find other reasons, you should consider replacing the thyristor together with the radiator.

Because the thyristor and other components are precisely connected, other components will be burned at the same time, and other related components must be thoroughly inspected for damage before replacing the thyristor. Otherwise, if you only replace the thyristor, it may burn out immediately, and it may also cause a bigger failure.

This is an energy storage spot welding machine, the left part is to cross the flow to DC, and then through a thyristor and the resistance below to form a loop, for the energy storage electrolytic capacitor to charge (several components, the symbol letter is really invisible), this thyristor controls whether the capacitor is charged or not.

The right part is four thyristors to discharge the energy storage capacitor to the welding transformer for welding, and the reason why four thyristors are used to discharge the welding transformer is to change the current direction of each welding of the transformer and reduce remanence. For example, the first welding of thyristor one, three trigger conduction; In the second spot welding, the thyristor two and four trigger conduction.

Each time a SCR soldering is triggered, the SCR charged with the left capacitor must be turned off, otherwise a short circuit will be caused.

Diodes and thyristors are often used at the same time, and each component plays a different role, which cannot be analyzed by a single product, depending on the actual R&D requirements.

1. To be precise, diodes and unidirectional thyristors can be rectified, first of all, the definition of rectification: turning AC into DC is called rectification, 2. General rectifier circuit, when there are no special requirements, use diodes to rectify, use one-way thyristors to switch control when rectifier switch control is required, and adjust the conduction angle of the thyristor to control the energy when you need to adjust the output energy.

3. Diodes and thyristors have working current, on-voltage drop, reverse breakdown voltage, and size 4. Inverter definition: turning DC into AC is called inverter, and the inverter circuit is composed of many devices, not which single device can complete it.

The diode can be rectified; The thyristor is not a rectifier element, it cannot be rectified, it is a switching device.

The inverter needs to first turn the direct current of the battery into pulsating alternating current through the ** device, and then turn it into 220V alternating current through the boost circuit.

There are many ways to make inverter power supply oscillators, common ones are: transistor oscillators, integrated circuits (NE555 CD4069, etc.) oscillators, etc., thyristors here are not rectifications, but to replace the role of high-power triode output.

As for power, generally 100W inverter power supply needs a high-power transistor of more than 25A for output. Of course, the same is true with thyristors.

The diode can be rectified; Thyristor is also a rectifier element, can rectify, diode or thyristor rectification, which is better? As required.

In the electronic converter circuit, the single-phase bridge rectifier of the rectifier part is the single-phase rectifier circuit with the most practical applications. The three-phase bridge rectifier is the most widely used method in the power system, especially the generator excitation system. Both circuits are connected to freewheeling diodes.

Its function is roughly the same, taking the single-phase bridge circuit as an example: when the controllable rectifier bridge is connected to the inductive load, because the inductor current can not be abruptly changed, during the shutdown period of the thyristor, the freewheeling diode must be connected at both ends of the load to maintain the path of the inductor current, so as to prevent the dangerous overvoltage and the thyristor can be commutated conduction at both ends of the inductive load when the thyristor is turned off. However, the three-phase bridge rectifier circuit that is widely used in the generator excitation system is divided into three-phase half-control bridge and three-phase full-control bridge circuit.

Therefore, in order to ensure reliable commutation of the rectifier elements, the half-control bridge needs to be connected with freewheeling diodes in parallel at both ends of the inductive load, while the full control bridge does not need to do this. When the conduction angle changes, the average voltage and line current of the half-bridge change more slowly than that of the full-bridge bridge. Nowadays, the equipment used more such as inverter contains rectifier and inverter and other converter circuits, in which the freewheeling diode used is generally added to the DC bus inside the inverter, that is because if the load is an inductive element, when the large-capacity inverter on the bus fails, the DC bus will produce a huge reverse surge energy, at this time, we need to provide a discharge channel for these energies, otherwise the huge energy will break down or burn the small inverter.

This channel needs a diode to compose, so it should be a freewheeling diode. About this suggestion, go to the official website of the hard city to see, it can quickly solve the problem and the service attitude is good, which many places can't do.

Hello! The line of the transformer is too large, resulting in the output current is too high, the current of 307 is 3 amps, your output may be more than 3 amps, so it will burn, you can use two 307 into one, and you can use 4 to double the voltage.

If it helps you, hope.

What causes the high-power inverter to burn the diode repeatedly.

13009 is not a thyristor, it is a triode. It can be used on oscillation circuits.

The output of the transformer needs to be directly used by the Huaizi cover, and if it is not connected to the power grid, it belongs to passive inverter. In this case, since there is no voltage fluctuation at the output, the inverter needs to be tightly controlled on and off, so it is necessary to use a fully controlled device such as a thyristor that can be turned off.

As long as the working current of the two elements is the same, the thyristor with a withstand voltage of 1200V can be replaced by a thyristor with a withstand voltage of 800V, but it is slightly higher.

Hello: Replacing thyristors with high voltage resistance is [Yes], the safety factor is higher, but [Current ratingBy all meansGreater than, equal toThe original rated current value, otherwise it is easy to burn.