What is a DC welding machine, the difference between a DC welding machine and an AC welding machine

Direct current. A welding machine is an electric welding machine with an output power supply of DC power supply.

It has the advantages of easy arc striking, arc stability and welding. The DC welding machine can be said to be also a high-power rectifier.

Generally speaking, workpieces with high welding quality requirements are welded by DC welding machine.

The basic principle of DC welding machine.

The DC welding machine can be said to be also a high-power rectifier, divided into positive and negative electrodes, alternating current.

When input, after transformer transforming, then rectified by the rectifier, and then output the power supply with descending external characteristics, the output terminal will produce a huge voltage change when it is turned on and off, and the two poles ignite the arc when it is instantaneously short-circuited, and the generated arc is used to melt the welding electrode and welding consumables, and the purpose of combining them is achieved after cooling. The welding transformer has its own characteristics, and the external characteristics are the characteristics of the voltage dropping sharply after the electrode is ignited.

Technical specifications of DC welding machine.

The DC power supply can provide a stable arc and a smooth transition of molten droplets, once the arc is ignited, the DC arc can maintain continuous combustion; The DC arc has a good wetting effect on the molten weld metal and can standardize the weld bead size, so it is very suitable for welding thin parts. DC power supply is more suitable for vertical welding and vertical welding than AC power supply because the DC arc is shorter.

The output of the DC welder is direct current.

There are DC inverters, and there are thyristors.

What is AC Welder and DC Welder Machine? The welder will teach you how to distinguish, learn it!

First, the working principle is different.

1. Direct current.

Welding machine: When the DC welding machine works, the alternating current is applied first.

After rectification and filtering, it becomes direct current. In order to improve the welding performance, dynamic reaction speed and efficiency of the welding machine, it is necessary to pass direct current through the high-power thyristor.

It is inverted into medium, high and low voltage alternating current, and then rectified to output a smooth DC current.

2. AC welding machine: AC welding machine is essentially a special step-down transformer, and the welding rod and welding parts are connected to the two output ends of the power supply respectively.

Second, the characteristics are different.

1. DC welding machine: Because the medium and high frequency AC power is more inductive reactance than the power frequency AC, the transformer core and the number of turns can be reduced, the response speed is faster, and the arc is easier and more stable.

2. AC welding machine: by changing the reactor.

The length of the air gap, the output current of the transformer will increase as the air gap grows.

Third, the advantages are different.

1. DC welding machine: DC welding machine is small in size, light in weight and easy to move, but it is expensive.

2. AC welding machine: DC welding machine is easy to start arc, the arc is stable, not easy to break the arc, and the spatter is small.

Applications:1Sheet welding.

Welding of various thin-walled and thin-plate workpieces such as bellows, sensors, etc.

2.Medical equipment, instrumentation.

Tools, fixtures, pipe fittings, thermocouples, motors, silicon steel sheets, precision components, etc. 3Automotive, Aircraft & Aerospace.

valves, pipe fittings, spacecraft hydrogen tanks, cooling pipes, etc.).

4.Welding of special metals.

Special metals such as titanium, nickel, molybdenum and other special metals can also be welded efficiently.

Functional configuration: precision pulse (imitation laser) features:

1. The output of small current is stable, and the arc is stable in 2A, which can meet the welding of thin-walled, fine and precision parts.

2. The welding current output time is accurately controlled, up to 1 1000 seconds.

3. High welding precision, low thermal impact, to achieve laser welding effect.

4. The welding deformation is small, and there is no deformation and undercut.

5. The welding strength is high, and various mechanical processing can be carried out.

6. Non-professionals, can be operated after short-term training.

Technical characteristics of welding machine:

1.Digital, using DSP processor, the output is accurate and precisely controlled.

2.Manufactured with high-quality components for reliable performance.

3.Multi-group data storage, up to 99 groups, easy to operate.

Working principle inverter 021-60496511

AC welders and DC welders are better to use than DC welders.

Compared to AC power sources, DC power supplies provide a stable arc and smooth melt droplet transition. - Once the arc is ignited, the DC arc can maintain continuous combustion. When using AC power for welding, due to the change of current and voltage direction, and the arc has to be extinguished and re-ignited 120 times per second, the arc cannot be continuously and stably burned.

Composition of DC welding machine:

1. The power supply is the core part of the electric welding machine, which is mainly composed of a power supply unit, a voltage stabilization circuit, a regulating circuit and a protection circuit. The power supply unit is used to convert the mains power into direct current, the voltage regulator circuit is used to control the voltage of the power supply output, the regulation circuit is used to control the current output of the power supply, and the protection circuit is used to protect the power supply from damage.

2. The welding mechanism is an important part of the electric welding machine, which is mainly composed of electrode handle, welding cable, welding head and welding pliers. The electrode handle is used to hold the welding electrode, the welding cable is used to connect the power supply to the welding head, the welding head is used to connect the electrode to the welding pliers, and the welding pliers are used to keep the welding electrode in close contact with the welding material.

3. The control mechanism is an important part of the electric welding machine, which is mainly composed of a power controller, a welding controller and a protection device. The power controller is used to control the output voltage and current of the power supply, the welding controller is used to control the welding process, and the protection device is used to protect the welding machine from damage.

4. The heat source mechanism is an important part of the electric welding machine, which is mainly composed of heating elements, melting elements and protective elements. Heating elements are used to convert electrical energy into heat, molten elements are used to melt the welding material, and protective elements are used to protect the welding machine from damage. <>

Generally, the DC inverter welding machine is to meet the requirements of the dynamic and static characteristics of the welding process.

First of all, it is necessary to choose the appropriate welding power source (DC output 400A is recommended).

Then it's time to design a reliable circuit structure. IGBT can be used as a power electronic device to form a single-ended forward inverter main circuit, and the low-power IGBT parallel type and two-way inverter arc welding power supply can be used in parallel to meet the requirements of large-capacity output. The control circuit of the system uses pulse-width modulation technology (PWM) and the PWM modulator adopts the typical integrated circuit SG3525.

The working characteristics of the system are as follows: when the welding arc is working normally, the PWM control mode is adopted, the inverter frequency is set to 20kHz, and the constant current external characteristics are controlled; The system uses voltage feedback control to make the PWM modulator output pulses intermittently when there is no load, and the frequency of intermittent oscillation is low and the pulse width is narrow, which not only has small no-load loss, but also makes the transformer not easy to saturate.

The system adopts the control mode of short-circuit frequency division for the short-circuit process of the welding arc, and controls the short-circuit current. The system also adopts a small given value and a minimum pulse width control circuit, which makes the welding easy to start arcing, the welding arc is stable, and the welding characteristics are good.

An electric welding machine is a device that uses arc heating to melt metal and use this method to join different metal parts. DC and AC are two different types of current, and they are used in welding machines in the following ways:

1.DC Current: The current has only one direction in the circuit, i.e., from the positive to the negative.

In electric welding machines, DC current is mainly used to weld different types of metals, especially high conductivity materials such as aluminum alloys and stainless steel. In this case, the use of direct current can provide better weld quality and stability. Direct current can also make the welder more thermally efficient.

At DC current, the arc between the electrode and the workpiece is relatively stable and easy to control.

2.AC current: The current changes direction back and forth in the circuit, i.e., the positive and negative electrodes alternate.

In electric welding machines, AC current is mainly used to weld materials such as thinner steel plates. The use of alternating current creates more frequent and unstable arcs, which makes the welding less efficient and the quality of the weld poor. However, in some special cases, it may be more effective to use AC current to weld different types of materials, such as copper and zinc, among others.

It should be noted that the welding machine needs to choose the correct type of current in actual operation, which depends on factors such as the type and thickness of the material being welded. For different materials and preservation, it is best to operate according to the instruction manual of the welding machine. When using it, you also need to pay attention to protecting yourself and reducing the risk of fire to ensure safety.

DC and AC of a welding machine refer to the type of output current it has.

The direct current (DC) output current direction does not change, and is usually used to weld metal materials. In DC welding, the positive electrode is connected to the workpiece, and the negative electrode is connected to the electrode or tungsten electrode. Since the heat is mainly concentrated on the workpiece, a deeper, more stable weld seam can be obtained.

The direction of the alternating current (AC) output current changes periodically, and can also be used for welding metal materials in some special cases. However, in contrast, AC is more effective at removing surface contaminants such as oxides and can reduce slag generation.

It should be noted that when choosing which type of power supply to use, you need to judge and choose on a case-by-case basis. For example, the use of AC in high-frequency conditions may cause overheating and damage to the device; In some special occasions such as aluminum alloy and other materials, it is necessary to use a DC inverter type power supply specially designed to handle such materials to achieve the best results.

There are three differences between DC welding machine and AC welding machine: 1. The process technology of DC welding machine and AC welding machine is different; 2. DC welding machine is replacing AC welding machine; 3. DC welding machine can save energy and reduce emissions.

Specific differences: 1. The DC welding machine mainly welds more important items such as boilers, pressure vessels and alloy structural steel, and generally uses alkaline electrodes for welding equipped with DC welding machines, and the alkaline electrodes have good crack resistance and mechanical properties at the weld after welding. AC welding machines mainly weld materials such as mild steel or alloy structural steel with low strength.

2. The advantages of DC welding machine are that the items finished with welds are beautiful, have a stable arc, and have low spatter and low air consumption during use; The AC welding machine generally uses acid electrodes for welding.

3. Although the DC welding machine has many advantages, the fly in the ointment is the poor process performance; Although the acid electrode can be used in the AC and DC welding machine, the mechanical properties of the weld are relatively low, especially the impact toughness is poor. However, the welding process performance ratio is still quite good.

First, it works differently.

Welding machine: When working, the DC welding machine will turn the alternating current into direct current after rectifying and filtering. In order to improve the welding performance, dynamic response speed and efficiency of the welding machine, it is necessary to convert direct current into medium and high frequency, low voltage alternating current through high-power thyristors, and then rectify and output stable direct current.

2.AC welding machine: AC welding machine is essentially a special step-down transformer, and its welding rod and welding parts are connected to the two output ends of the power supply respectively.

Second, the characteristics are different.

Welding machine: DC welding machine is easy to start the arc, the arc is stable, not easy to break the arc, and the spatter is small.

2.AC welding machine: AC welding machine has a simple structure and low maintenance cost, while DC welding machine has a complex structure and is difficult to maintain.

Third, the advantages are different.

Welding machine: DC welding machine is small in size, light in weight, easy to move, but expensive.

2.AC welding machine: AC welding machine is large, heavy, and not easy to move, but relatively cheap.