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| The device of welding rectifier (transformer with moving coils) |
The power transformer converts the energy of the power network in the energy required for welding, as well as agree on the values of voltages to the output voltage. In the single-station rectifiers are used primarily three-phase transformers as single-phase single-and full-wave rectification results in a significant output voltage ripple, which degrade the quality of welded joints.
Regulators of the current (or voltage regulators) are used to form a rigid or falling outside specifications. They allow you to set the appropriate value of welding and welding current.
Rectifier unit is mainly collected at the three-phase bridge circuit, at least - for single-phase full-wave bridge rectifier. For three-phase bridge circuit provides more uniform loading of three-phase power line and achieved high technical and economic indicators. As semiconductors are used selenium or silicon valves.
Types of welding rectifiers
Depending on the design of the power of the welding rectifiers are divided into the following types:
- adjustable transformer;
- with the choke saturation;
- thyristor;
- with transistor regulator;
- inverter.
For mechanized welding under flux or shielding gas in welding equipment with self-regulation using single-station arc rectifiers with rigid external characteristics. Usually in such a transformer rectifiers used with a normal magnetic scattering. Possible methods of welding voltage
- Vitkovo regulation - in the welding rectifier transformer with sectionalized coils;
- magnetic control - in the rectifier transformer with magnetic switching or choke saturation;
- phase regulation - in the thyristor rectifier;
- impulse control - latitude, frequency and amplitude control in the rectifier with a transistor inverter, rectifier and regulator.
- series aircraft (VS-200, BC-300 BC-400 BC-500 BC-600 BC-632), EDC (EDC-301 EDC-302 EDC-303 EDC-603) and SCW (SCW -303);
- as well as welding rectifiers BC-1000 BC-1000-2 for the mechanized welding in argon, helium, carbon dioxide, submerged.
- increasing the resistance of the transformer - in welding rectifier transformer with moving coils, the magnetic shunt or with spaced windings;
- the use of current feedback - in the thyristor, transistor inverter or rectifier.
A very popular and versatile welding rectifiers that shape both the incident and rigid specifications. The best known types are:
- Series VSC (VSC-150, FAC 300, FAC-500) for manual arc welding with coated electrodes, semiautomatic and automatic gas-shielded welding;
- series APU (APU-300, DSR-500) and TPL (TAL-504 TAL-305 TAL-1201, TAL-1601) for manual welding with coated electrodes, mechanized welding wire melting electrode submerged arc welding, gas shielded, flux-cored wire .
The power section consists of a rectifier transformer and rectifier unit with power diodes.
In such rectifiers are commonly used three-phase transformers with increased magnetic scattering - with moving coils or magnetic shunts.
Welding governed combined: step by step through the switching transformer with a "star" in the "triangle" and smoothly, for example, by changing the gap between the windings of the transformer.
Welding rectifiers with hard features and adjustable transformer
The power section consists of a rectifier transformer, rectifier and smoothing reactor block.
Due to throttle down the rate of increase of welding current and the peak in the excitation of the arc, as well as reduced spattering of molten metal during welding consumable electrode (wire).
In welding rectifiers aircraft type used step voltage control - switching the number of turns of the windings.
In rectifiers type SCW (SCW-303) is applied smoothly step regulation. Stepless control of welding by means of a transformer with a magnetic switching.
Welding rectifiers with inductor saturation
Choke saturation used in the construction of rectifiers, forming both the incident and stringent specifications.
A typical representative of the rectifier with choke saturation and external characteristics of a steeply dipping Welding rectifier VD-502.
It uses the power three-phase transformer with a normal magnetic scattering, single-ended inductor saturation, performed on three separate cores with a winding control, and three-phase rectifier unit with a bridge circuit. Rectifier mode of operation is configured by changing the inductor saturation.
A typical representative of the rectifier with choke saturation and rigid external characteristics - Welding Rectifier EDC-302.
It uses a smooth-step regulation of the current-voltage characteristics. Stepwise regulation is carried out by changing the transformation ratio of the power of three-phase transformer with a normal magnetic scattering. With the help of a packet-switch cam primary winding of the transformer are mounted on three working position.
Modulating within each step is performed a three-phase symmetrical choke saturation performed on six pairs of tape cores combined. The first step of regulating the voltage corresponds to the connection of the primary winding of phase "triangle" with the use of elbows, the second stage of regulation - the connection of the windings of phases "triangle" with no bends, the third level of regulation - the connection phase windings with taps "star".
Three-phase rectifier unit has a bridge circuit with uncontrolled rectifiers.
Control winding is fed through the inductor saturation stabilizer and rectifier unit 1. Winding inductor saturation bias is supplied from the secondary winding of the transformer through a rectifying block 2.
See also:
manual arc welding
semi-automatic welding
argon-arc welding (argon welding)
Welding Equipment:
Welding Transformers
Welder
Welding Rectifiers
Welding Inverter
Welding Machines
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