To begin with, the choice of alternating current or direct current for welding depends on the coating of the electrode itself, as well as on the type of metal with which it is necessary to work. In other words, using a welding transducer to obtain a constant current, which means a more stable arc for operation, is not always possible.
What is a converter?
A welding transducer is a combination of several devices. It uses a bunch of electric AC motor and a special welding machine with direct current. The process of energy conversion is as follows. Electric energy coming from the AC mains acts on the electric motor, causing the shaft to rotate, creating mechanical energy due to electric. This is the first part of the conversion. The second part of the operation of the welding transducer is that during the rotation of the generator shaft, the generated mechanical energy will create a constant electric current.
However, it is immediately worth noting that the use of such devices is not very popular, since their efficiency is small. In addition, the engine has rotating parts, which makes its use not very convenient.
The principle of operation of the device
It can be noted that the welding transducer is a specific type of ordinary welding machine. In short, the design of this equipment is about the following. There are two main parts - this is the electric motor, which is most often asynchronous, as well as a DC generator. The peculiarity is that both of these devices are combined in one housing. It is also important to pay attention to the fact that the circuit has a collector. Since the operation of the generator is based on electromagnetic induction, it will produce alternating current, which will be converted into direct current using a collector.
If we talk about the principle of operation of the welding transducer, then do not confuse it with such devices as a rectifier or inverter. The end result for all three devices is the same, but the essence of their work is very different. The biggest difference is that the converter has a longer conversion chain. Since alternating current is first converted into mechanical energy and only then into direct current.
Welding Converter Device
Consider the device of this device by the example of a single-post converter. Such models consist of a conventional drive induction motor and a welding generator, combined in one housing.
It is worth noting that such equipment is intended for outdoor use. However, there they must be placed either in specially designated places - machine rooms, or under awnings. This is necessary to protect electrical equipment from precipitation.
Unit internal arrangement
If you go into the details of the device and design, as well as the principles of operation of the welding transducer, then all this looks as follows.
Since the device heats up during the operation of the device, a fan is mounted on the shaft between the generator and the electric motor to cool the converter. The electromagnetic parts of the generator, that is, its poles and anchor, are made of thin sheets of steel of an electrical grade. On the magnets of the poles are elements such as coils with windings. The anchor, in turn, has longitudinal grooves into which the insulated winding is laid. The ends of this winding are soldered to the collector plates. This device also has ballasts and an ammeter. Both devices are located in a box.
Used models
At present, welding converters with a nominal welding current of 315 A are used. The main purpose of these units is to supply direct current to one welding station. It can also be used to power manual arc welding, surfacing and metal cutting with piece electrodes. In converters of this kind, generators of the GSO-300M and GSO-300 types are used. Their device is a four-pole DC collector machine with self-excitation. The difference between these two models from each other lies only in the fact that they have different rotational speeds of the generator shaft. This applies to welding transducer 315. 500 A is the second rated current, which is also used for operation. However, it is already necessary to connect a more powerful converter, for example, the PD-502 model. A significant difference between such a converter model and GSO is that it has independent excitation. The point here is that an AC three-phase current is used to power the PD-502, which first passes through an inductive-capacitive voltage converter. Along with the power function, it also acts as a stabilizer for this model of the unit.
However, it is important to understand that the main purpose of the welding transducer is to convert the energy of an electric type of variable nature into electrical energy of a constant nature.
Types of Converters
There are two main types of transducers - these are stationary and mobile. If we talk about stationary types, then most often these are small welding booths or posts designed to work with small volumes of products. The welding transducers installed here do not have high power.
Mobile, in turn, are designed mainly to work with large volumes. They are often used to weld water pipes, oil pipelines, metal structures, etc.
It is important to add something more about the principle of operation of this device. As mentioned earlier - it converts alternating current to direct, using the transition to mechanical energy. However, there are some devices that allow you to adjust the value of the output DC current. The adjustment process is carried out using devices such as ballast rheostats. The principle of operation is quite simple - the higher the resistance value set, the lower the output DC voltage and vice versa.
Terms of Use
Using a welding transducer, you must adhere to some rules. For example, the device terminals should not be closed under any circumstances, since the voltage on them is 380/220 V. Another important rule is that the converter housing must always be reliably grounded. People working directly with such equipment must be protected with gloves and masks.