How to make a current regulator for a welding machine

Current regulator circuit for a welding machine

The quality of the weld depends largely on the characteristics of the electric arc. For each thickness of metal, depending on its type, a certain strength of welding current is required.

In addition, the current-voltage characteristic of the welding machine is important; the quality of the electric arc depends on it. Cutting metal also requires its own electric current values. That is, any welding machine must have a regulator that controls the welding power.

Methods of regulation

The current can be controlled in different ways. The main methods of regulation are:

• introducing a resistive or inductive load into the secondary winding of the welding machine;
• changing the number of turns in the secondary winding;
• change in the magnetic flux of the welding machine;
• use of semiconductor devices.

There are many schematic implementations of these methods. When making a welding machine with your own hands, everyone can choose a regulator according to their taste and capabilities.

Resistor or inductance

Adjusting the welding current using a resistance or inductor is the simplest and most reliable. A powerful resistor or inductor is connected in series to the welding electrode holder. Due to this, the active or inductive resistance of the load changes, which leads to a voltage drop and a change in the welding current.

Regulators in the form of resistors are used to improve the current-voltage characteristics of the welding machine. A set of powerful wire resistances or one resistor made of thick nichrome wire in the form of a spiral is used.

To change the resistance, they are connected to a specific turn of wire using a special clamp. The resistor is made in the form of a spiral to reduce its size and ease of use. The resistor value should not exceed 1 ohm.

Alternating current at certain times has zero or close to it values. At this time, a short-term arc extinguishing occurs. When the gap between the electrode and the part changes, sticking or complete extinguishing may occur.

To soften the welding mode and, accordingly, obtain a high-quality seam, a regulator is used in the form of a choke, which is connected in series with the holder in the output circuit of the device.

The additional inductance causes a phase shift between the output current and voltage. At zero or close to zero values ​​of alternating current, the voltage has a maximum amplitude and vice versa. This allows you to maintain a stable arc and ensures reliable ignition.

The choke can be made from an old transformer. Only its magnetic core is used, all windings are removed. Instead, 25-40 turns of thick copper wire are wound.

This regulator was widely used when using AC transformer devices due to its simplicity and availability of components. The disadvantages of the welding current throttle regulator are the small control range.

Changing the number of turns

With this method, the arc characteristics are adjusted by changing the transformation ratio. The transformation ratio can be changed by additional taps from the secondary coil. By switching from one tap to another, you can change the voltage in the output circuit of the device, which leads to a change in arc power.

The regulator must withstand high welding current. The disadvantage is the difficulty of finding a switch with such characteristics, a small range of adjustments and discreteness of the transformation ratio.

Magnetic flux change

This control method is used in transformer welding machines. By changing the magnetic flux, the efficiency of the transformer is changed, this in turn changes the value of the welding current.

The regulator operates by changing the gap of the magnetic circuit, introducing a magnetic shunt or moving the windings. By changing the distance between the windings, the magnetic flux is changed, which accordingly affects the parameters of the electric arc.

Source: https://vi-pole.ru/shema-reguljatora-toka-dlja-svarochnogo-apparata.html

Types and settings of current regulators for a welding machine

Each control method can have a positive effect on the operation of the welding unit, but each method also has its own disadvantages, which it is advisable to know and be able to avoid unpleasant situations. The welding process is a responsible procedure, therefore it determines almost any deviation from the norms.

Using special regulators:

• The operating current is adjusted,
• The magnetic flux changes.

Therefore, the current regulator for a welding machine performs an important function and the main methods of regulation are: magnetic shunting, mobility of windings, as well as various types of chokes.

Methods for adjusting welding parameters

If you connect to the taps that are made on the second winding of the transformer, then there is the possibility of stepwise regulation of the electric current. When using this method, the number of turns changes, thus reducing or increasing the current.

But there are disadvantages to this method, which lie in the minimum adjustment ranges. And the control device will have to be of decent dimensions in order to withstand serious electrical overloads. You will also have to use powerful switches that can withstand high currents.

The secondary winding takes up significantly greater loads than the secondary winding, so this device wears out quickly. To improve the performance of this design, thyristors are used, which are integrated into the primary winding.

With the help of such a device, you can configure the welding machine, and it is very simple to do. To make a current regulator for a welding machine, you need to correctly select the resistances and other elements included in the circuit of this device.

Current regulator circuit for a welding unit

The thyristors in the device are installed in parallel so that they are turned on by the current generated by the two transistors. When the regulator is connected to the circuit, the thyristors are in the closed state, and the capacitors receive the charge due to variable resistance.

And when the capacitor reaches a certain voltage, the discharge current moves. After the transistor, the thyristor opens, connecting the load.

By changing the resistance of the resistor, it will be possible to adjust the connection of the thyristors. In this regard, the total current on the original transformer winding changes.

To achieve an increase or decrease in the adjustment range, the resistance of the resistor changes in the desired direction. If transistors are not available, the use of dinistors is an acceptable condition.

Regulator circuit with dinistors and transistors

A current regulator for a welding machine is mounted not only on transistors designed to produce an avalanche voltage, but also using dinistors.

This element must be connected with its anodes to the resistance terminals, and with its cathodes it must be connected to the other two resistors. Transistors of models P416, GT308 are used for regulators of welding devices, but there is also the possibility of connecting low-power transistors with similar characteristics.

Variable type resistors can be used SP-2, and MBM are used as permanent elements. In this case, it is necessary to select a resistance that will have a suitable operating voltage.

In order to properly assemble a control device for a welding machine, you need to use a textolite base with a thickness of 1.5 - 2 millimeters, then the installation process will be more convenient.

It is necessary to ensure that all parts involved in the circuit are insulated from the housing, since short circuits and an increase in temperature are possible. Serious overloads can lead to negative consequences and failure of both individual elements and the entire device.

If all the rules were followed when assembling the control device, and the parts were selected according to optimal parameters, then the regulator does not need to be adjusted.

But before using the device in full, you need to check the operation of the transistors included in the circuit, because they may not withstand the avalanche mode.

Thanks to the stable operation of the device, welding machines will be able to work normally with different materials and structures being welded.

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Source: https://swarka-rezka.ru/tipy-i-nastroyka-regulyatorov-toka-dlya/

Twist welding machine: what is it, how to make it yourself

When replacing wiring, a twist welding machine is required. Most often, the devices are used when renovating an apartment. Copper wires unravel and need to be collected in order to fit compactly in the box.

What it is

A transformer is a device designed for soldering wires. If you look at the cut cable, its edges resemble bristles, with tendrils pointing in different directions. For ease of use of the wires, it is required that the edges be gathered and smoothed. For this purpose, a transformer is used that connects the antennae by soldering.

Twist welding machine

Visually, it represents a large block (the transformer itself), from which the wires extend. Clamps are connected to them, as well as an electrode.

Important! Next to the transformer there is a voltage regulator.

Specifications

When considering transformers, the following indicators are taken into account:

• welding current;
• voltage level.

The voltage ranges from 12 to 36 volts, the welding current starts from 70 amperes to 120 amperes. Much depends on the preparations. If we consider elements with two wires, the welding current should be 70 amperes, provided that the cross-section does not exceed 1.5 square meters.

Advice! Selecting a cable with a cross-section of 2.5 square meters for four wires, the welding current should be 120 amperes.

How the device works

To connect copper wires, alternating, direct or rectified current is suitable. Its voltage value plays an important role. An electrode is used to melt the material, which does not violate the integrity of the metal.

Operation of the device

If you want to get an even, beautiful seam, you need to look at DC models. The melting process is carried out due to reliable contact of the electrode with the surface. In order to control the melting process, a current regulator is required.

The electrode should ideally not stick to the metal. The transformer is responsible for arc welding, so maintaining stable combustion is considered important. Since the device is used on copper, it does not have a high melting point. If we consider steel, we cannot do without a powerful transformer.

As a result, there is no need to achieve a large arc; only short-term exposure is required. As is the case with steel, there is no metal spattering. The electrode is made of carbon. Many DIYers use special rods that are taken from batteries.

As an option, brushes from electric motors are suitable.

When connecting the transformer to the network, the electrode should be brought almost closely to the copper; a gap of up to 1 mm is allowed. During the voltage conversion process, an arc appears and a small ball is visible at the end of the electrode. Since we are not talking about a high temperature, the metal will not become porous, that is, the insulation is not damaged.

Advice! When soldering is completed, the wire is cooled and it is advisable to cover its end with electrical tape.

How to make a wire welding unit with your own hands

If you wish, you can make a transformer for welding copper wires with your own hands. The main issue concerns the selection of materials and tools. During the manufacture of the device, it is better to follow the instructions.

Materials and tools

To make a device with your own hands, you will need the following materials from materials:

• transformer;
• alligator clips;
• carbon electrode;
• aluminum cable - 2 pieces;
• rotary voltage regulator;
• power cable with a cross-section of more than 2.5 mm.

Tools include pliers and a set of screwdrivers. It is advisable to have pliers on hand.

Step-by-step instruction

To make a transformer with your own hands, you must follow the instructions.

Case selection

For homemade products, you need a reliable casing that will protect the transformer. It is important to remember safety precautions, as it is easy to get burned. The box can be made of metal or plastic. If a mobile installation is being made, it is better to use plastic. A metal box is considered more stable, but is not intended for transportation.

Case selection

Transformer

Regarding the base, both electronic and power units are available to choose from. The blocks are supplied by various manufacturers and it is important to decide on the circuit of the thyristor welding device. The circuit provides space for output blocks as well as a secondary winding.

A voltage regulator is selected separately, which is responsible for the rectified current. This technology is actively used to charge batteries. Therefore, similar settings are found in starters from various manufacturers. If the choice falls on an electronic unit, it’s worth understanding its operation a little. The signal generator circuit is taken as the basis, so bipolar transistors are used. Reverse conduction is ensured and high voltage is observed.

Transformer circuit

When selecting an electronic unit, the maximum level of energy consumption, as well as voltage, is taken into account. Homemade modifications for 6 and 9 volts are considered common. In the standard circuit of the electronic unit, the transistors are opened and then the capacitors are discharged along the chain. The thyristor in the circuit works as an amplifier.

As an option, three-winding transformers of the TI series are used. Their peculiarity is their low voltage level. If desired, the element can be created independently on ferrites. Such installations have a high energy conversion rate. During assembly, it is important to achieve the required current value, which depends on the needs.

Power cable

When there is a powerful 24 volt transformer, it is recommended to select the appropriate electrical wiring for it. It is recommended to use blanks with a cross-section of 2.5 mm or more. For safety reasons, it is recommended to install a switch that is connected to the wiring. Thus, if something happens, the installation can be quickly turned off by stopping the current supply.

Power cable

Using Terminals

To power a transformer or inverter, terminals are attached to it using the twisting method. Next, you connect to a 220 volt network.

Mounting the holder and contact

Two wires come from the terminals, one of which goes to the holder, the other to the contact. The welder must be able to hold the workpiece, as well as freely fix the electrode, thanks to which welding is carried out. Specialists do not always use clamps, preferring to work freely with pliers. When taking a closer look at the electrode holder, it is recommended to select long blanks, as they are more practical.

Device holder

The risk of electric shock is reduced, plus it is more practical for the welder to work in hard-to-reach places. The long holder makes it easy to work on the ceiling or in narrow passages. Additionally, if there is a long holder coming from the transformer, there is no need to move it frequently.

How to use it correctly

When using the device, welding experience is required. The main goal is to achieve a high-quality connection; the seam should be smooth and neat. Most often you have to work with a cable of small cross-section. Not all devices are suitable for soldering twists. If we consider the modification with alternating current, it is important to feel the power of the transformer.

When connecting the equipment, the first thing to do is check the electrode and power cable. It is important to clean the wire so that there is no buildup on it. The cores must be stripped of insulation with a margin of 6 cm. During the melting process, it is important to ensure that the insulation is not affected. Before melting, the twist is checked.

Checking twist

Inexperienced welders, the conductors fit unevenly, so it is not possible to make an accurate drop. After twisting, trimming is done. All tendrils must be removed to make the cut look neat. Thus, the surface is heated evenly and the drop just falls on the edge. While working with the electrode, it is important to hold the workpiece with pliers.

The above describes in detail how to make a transformer with your own hands. This does not require special tools or materials. The unit is indispensable during home renovation work.

Source: https://rusenergetics.ru/instrumenty/apparat-dlya-svarki-skrutok

Do-it-yourself current regulator for a welding machine

» Articles » Do-it-yourself current regulator for a welding machine

Each control method can have a positive effect on the operation of the welding unit, but each method also has its own disadvantages, which it is advisable to know and be able to avoid unpleasant situations. The welding process is a responsible procedure, therefore it determines almost any deviation from the norms.

Using special regulators:

• The operating current is adjusted,
• The magnetic flux changes.

Therefore, the current regulator for a welding machine performs an important function and the main methods of regulation are: magnetic shunting, mobility of windings, as well as various types of chokes.

Welding current regulator

To conveniently adjust the welding current in household welding machines, various methods are used, from switching taps in the primary and secondary windings of the transformer to extinguishing the welding current using ballast resistors. The most advanced solution is to use an electronic welding current regulator for these purposes.

This regulator is available for independent repetition and has good performance both in terms of weld quality and energy consumption. The scheme is quite simple and can be implemented by a beginner radio amateur.

The transformer must be taken with a power reserve of 3 kilowatts. For such power, the primary winding must contain approximately 200–240 tons of turns of wire in PSD insulation with a cross section of 5 mm². The secondary power winding is made with a cross-section of 16mm² and higher.

The primary and power windings must be separated into different cores. For a better coupling coefficient, you can wind 3-4 turns of the power secondary onto the primary winding.

It is necessary to space the windings for a softer welding process; when winding the secondary winding and the primary winding on each other, the coupling coefficient is good, but the machine welds hard and the solution to the problem can only be the use of a smoothing choke at the output, which will eliminate voltage dips when crossing zero. Sometimes this doesn't help either.

A well-wound apparatus should sing in an arc, softly hissing, as if it were frying lard. Select the voltage of the secondary winding in the range of 50–55V with a transformer power of 3.0–3.5 kW, the welding current can reach 200–220A.

The welding current regulator proposed here works on several homemade welding machines, as well as on a welding arc produced by JSC Elektropribor. The standard factory adjustment block was removed, two additional windings were wound to power the electronic circuit, plus two thyristors were inserted and there are power diodes there. There is also a throttle at the output, so the unit in the frame is excluded. The alteration did not affect the quality of welding.

You can see an analogue of the arc welding machine here. This charger-starter Arc 318P differs from the welding machine only in the output voltage and bridge rectifier. Here they created a miracle. So implement the welding current regulator on any machines. This scheme works well.

Source: https://samsvar.ru/stati/regulyator-toka-dlya-svarochnogo-apparata-svoimi-rukami.html

DIY power regulator for welding transformer

» Articles » Do-it-yourself current regulator for a welding machine

Each control method can have a positive effect on the operation of the welding unit, but each method also has its own disadvantages, which it is advisable to know and be able to avoid unpleasant situations. The welding process is a responsible procedure, therefore it determines almost any deviation from the norms.

Using special regulators:

• The operating current is adjusted,
• The magnetic flux changes.

Therefore, the current regulator for a welding machine performs an important function and the main methods of regulation are: magnetic shunting, mobility of windings, as well as various types of chokes.

Electronic adjustment of welding current

One of the main components of a truly high-quality seam is the correct and precise adjustment of the welding current in accordance with the task at hand.

Experienced welders often have to work with metal of different thicknesses, and sometimes the standard min/max adjustment is not enough for proper work. In such cases, there is a need for multi-stage current regulation, accurate to the nearest ampere.

This problem can be easily solved by connecting an additional device to the circuit - a current regulator.

The current can be adjusted in the secondary (secondary winding) and in the primary (primary winding). Moreover, each method of setting up a transformer for welding has its own characteristics that are important to consider. In this article we will tell you how to regulate the current in welding machines, provide diagrams of regulators for a semi-automatic welding machine, and help you choose the right welding current regulator for the primary winding for a welding transformer.

Methods for adjusting current

There are many ways to regulate the current, and above we wrote about the secondary and primary windings. In fact, this is a very rough classification, since the adjustment is still divided into several components. We will not be able to analyze all the components within the framework of this article, so we will focus on the most popular ones.

One of the most commonly used current control methods is to add a ballast at the output of the secondary winding. This is a reliable and durable method; you can easily make a ballast with your own hands and use it without additional equipment. Often, ballasts are used solely to reduce current.

In this article, we described in detail the operating principle and features of using a ballast for a semi-automatic welding machine. There you will find detailed instructions on how to make the device at home and how to use it in your work.

Despite many advantages, the method of adjusting the current through the secondary winding when used in conjunction with a welding transformer may not be very convenient, especially for novice welders. First of all, the ballast is quite bulky and its size can reach a meter in length. The device is also often underfoot and gets very hot, and this is a gross violation of safety regulations.

If you are not ready to put up with these shortcomings, then we recommend that you pay attention to the method when the welding current is adjusted through the primary winding. For these purposes, electronic devices that can be easily made with your own hands are often used. Such a device will easily regulate the current through the primary and will not cause inconvenience to the welder during operation.

The electronic regulator will become an indispensable assistant for a summer resident who is forced to weld under conditions of unstable voltage. Often houses are simply not allowed to use electrical appliances larger than 3-5 kW, and this is very limiting in their work.

Using the regulator, you can configure your device so that it can operate smoothly even with low voltage. Also, such a device will be useful for craftsmen who need to constantly move from place to place while working.

After all, the regulator does not need to be dragged around like a ballast, and it will never cause injury.

Now we will talk about how to make an electronic regulator from thyristors yourself.

Thyristor regulator circuit

Above you can see a diagram of a simple regulator using 2 thyristors with a minimum of non-scarce parts. You can also make a regulator using a triac, but our practice has shown that a thyristor power regulator is more durable and operates more stably. The assembly diagram is very simple and according to it you can quickly assemble the regulator with minimal soldering skills.

The operating principle of this regulator is also simple. We have a primary winding circuit into which the regulator is connected. The regulator consists of transistors VS1 and VS2 (for each half-wave). The RC circuit determines the moment when the thyristors open, and at the same time the resistance R7 changes. As a result, we get the opportunity to change the current in the primary of the transformer, after which the current changes in the secondary.

Note! The regulator is adjusted under voltage, do not forget about this. To avoid fatal mistakes and avoid injury, it is necessary to isolate all radio elements.

In principle, you can use old-style transistors. This is a great way to save money, since these transistors can easily be found in an old radio or at a flea market. But keep in mind that such transistors must be used at an operating voltage of at least 400 V.

If you consider it necessary, you can put dinistors instead of transistors and resistors shown in the diagram. We did not use dinistors, since in this version they do not work very stably.

In general, this thyristor-based welding current regulator circuit has proven itself well, and on its basis many regulators have been manufactured that operate stably and perform their function well.

You could also see in stores the resistance welding regulator RKS-801 and the resistance welding regulator RKS-15-1. We do not recommend making them yourself, since it will take a lot of time and will not save you much money, but if you want, you can make RKS-801. Below you see a diagram of the regulator and a diagram of its connection to the welder. Open the pictures in a new window to see the text better.

Welding current measurement

Once you have made and configured the regulator, it can be used in operation. To do this, you need another device that will measure the welding current. Unfortunately, it will not be possible to use household ammeters, since they are not capable of working with semi-automatic devices with a power of more than 200 amperes. Therefore, we recommend using a clamp meter. This is a relatively inexpensive and accurate way to find out the current value; the clamp control is clear and simple.

The so-called “clamps” at the top of the device grip the wire and measure the current. There is a current measurement limit switch on the device body. Depending on the model and price, different manufacturers make clamp meters capable of operating in the range of 100 to 500 amps. Choose a device whose characteristics match your welding machine.

Clamp meters are an excellent choice if you need to quickly measure current without interfering with the circuit or connecting additional elements to it. But there is one drawback: clamps are absolutely useless when measuring DC current values. The fact is that direct current does not create an alternating electromagnetic field, so the device simply does not see it. But when working with alternating current, such a device meets all expectations.

There is another way to measure current, it is more radical. You can add an industrial ammeter to the circuit of your semi-automatic welding machine, capable of measuring large current values. You can also simply temporarily add an ammeter to the open circuit of the welding wires. On the left you can see a diagram of such an ammeter, according to which you can assemble it.

This is a cheap and effective way to measure current, but using an ammeter in welding machines also has its own characteristics. It is not the ammeter itself that is added to the circuit, but its resistor or shunt, and the dial indicator must be connected in parallel to the resistor or shunt. If you do not follow this sequence, the device, at best, simply will not work.

Instead of a conclusion

Source: https://respect-kovka.com/elektronnaya-regulirovka-svarochnogo-toka/

Do-it-yourself draft regulator for solid fuel boilers - Metals, equipment, instructions

Despite the popularity of gas heating systems, solid fuel boilers firmly hold their position in the domestic climate control equipment market.

In the minds of the average person, a boiler that runs on solid fuel is an ordinary potbelly stove.

In fact, modern solid fuel boiler equipment has a high level of safety and is capable of obtaining maximum thermal energy with a minimum of fuel.

Today, equipment is widely represented on the Russian market, thanks to which modern engineers have managed to significantly increase the level of comfort when using solid fuel units. This article will discuss devices that allow you to control the fuel combustion process and coolant temperature.

Traction regulator

The combustion process directly depends on the presence of air. If we transfer this statement to the operation of a heating device, then the more air enters the combustion chamber, the faster and at a higher temperature the fuel burns.

In other words: by supplying air to the fuel combustion chamber, you can regulate the degree of heating of the coolant. In the design of solid fuel heating systems, an air damper is provided for this function.

By changing the position of the damper, conditions are created under which fuel combustion occurs according to the pattern specified by the user.

The only problem: the owner of the boiler unit must adjust the position of the air damper manually, relying on the thermometer readings and his own experience. To automate this process, an automatic draft regulator was invented.

The device consists of a thermal element, a regulator, a metal lever and a chain. The thermoelement and regulator are assembled into a single housing made of heat-stable and corrosion-resistant steel. The thermostat is installed in the mounting socket until it comes into contact with the coolant circulating in the water jacket of the boiler unit.

The principle of operation of the regulator: when temperature affects the thermoelement, it changes its shape and, through the rod, acts on a lever, which is connected to the air damper of the boiler unit using a chain. When the coolant temperature changes, the position of the air damper automatically changes. The regulator sets the upper temperature limit.

To set up a draft regulator for solid fuel boilers with your own hands, you need to follow these steps:

• Install the regulator into the heating system. Depending on the boiler model, both horizontal and vertical installation of the device can be provided. Each installation option corresponds to a specific scale color on the regulator. At this stage the chain is not connected to the choke and hangs freely.
• Set (by selecting the color of the scale corresponding to the orientation) the desired temperature indicator of the coolant and start the boiler installation.
• When the coolant temperature reaches the value you set on the thermostat, close the air damper, leaving a gap of 2-3 mm.
• Attach the chain to the damper rod.

For the draft regulator to work correctly, the chain between the air damper and the thermostat draft must be tensioned.

https://www.youtube.com/watch?v=35SPAJB1Fyg

Let's digress a little, because we want to inform you that we have compiled a rating of solid fuel boilers by model. You can learn more from the following materials:

Automation for solid fuel boiler equipment

The traction control works great, but only when there are conditions for creating traction. The main problem with natural draft is weather dependence: the smaller the difference between the air temperatures outside and in the house, the worse the draft.

Modern sealed houses with metal-plastic windows, into which the flow of air mixture is completely absent or limited, also add fuel to the fire. To solve the traction problem, automation was invented.

By controlling the operation of the fan and circulation pump, the issue of stabilizing the temperature of the coolant is resolved.

Modern automation systems include:

• Controller with LCD display.
• Pressure turbine.

Some models include a pump that provides forced circulation of the coolant.

How to install and configure automation for a solid fuel boiler with your own hands? The controller reads information about the current coolant temperature directly from a thermocouple, which is always supplied with the automation unit and is installed at the outlet of the boiler circuit or in a technological hole intended for this purpose. The forcing turbine is installed instead of the air damper of a solid fuel boiler unit and connected to the controller. If a circulation pump is provided in this automation system, then it is connected to the controller terminals, and the controller itself is connected to a 220 v household network.

Use the coolant temperature selection keys to set the desired value. By changing the rotation speed of the blower fan blades, the controller regulates fuel combustion in the fuel chamber.

By regulating the performance of the circulation pump, the automation achieves more accurate compliance with user settings. Some models, in addition to the coolant temperature, read the temperature of the exhaust gases in the chimney.

This allows you to control the operation of smoke exhausters, which significantly increases the efficiency and safety of using solid fuel boilers.

Smoke exhauster for boiler installation

As noted above, natural draft does not always make fuel combustion and exhaust gas removal ideal. This happens for many reasons, the most common of which are: weather conditions and lack of air flow.

If air flow can be created by simply opening the windows, then it is impossible for an ordinary person to change the air temperature in the summer. In order not to depend on the draft in the chimney, users install a device called a smoke exhauster into the smoke removal system.

In addition, the use of a smoke exhauster allows less solid soot particles to settle on the walls of the chimney, and, accordingly, less need to resort to the services of a chimney sweep.

This is an exhaust fan mounted in a metal unit, which is mounted between the boiler and the mouth of the chimney. The picture shows the design of the exhaust fan.

Installing smoke exhausters for household solid fuel boilers with your own hands is quite simple:

1. Install the unit at the installation site of the smoke exhauster. For tightness, apply heat-resistant sealant to the joints.
2. Place the fan housing on the 4 studs with the impeller facing inward. Make sure that the gasket fits tightly to the exhaust fan mounting unit.
3. Place washers and nuts on the studs and tighten the fan assembly evenly.
4. Ground the device and connect the power plug to it.

Advice: to avoid electric shock, it is recommended to entrust all work on connecting the device to the electrical network to an electrician with the appropriate work permit.

Chimney for solid fuel installation

Speaking about the dependence of the operation of a solid fuel boiler on draft, one cannot help but touch upon the topic of arranging a chimney, thanks to which the combustion products are released into the atmosphere in a timely manner.

Modern boiler units with a closed combustion chamber are equipped with a coaxial smoke exhaust, which has many advantages and does not require it to be installed above the roof.

Most models of boiler equipment with an open combustion chamber require a stationary chimney, which must be in accordance with fire safety rules and have the necessary design to ensure unhindered removal of combustion products.

Source: https://spb-metalloobrabotka.com/regulirovka-toka-v-svarochnyh-apparatah-svoimi-rukami/

Adjusting the welding current for the electrode

Welding is the most reliable way to connect metal structures and products. The consumables used in this process are electrodes. Their composition is made in such a way as to best match the material being welded. The type of steel the welder works with is not the most important parameter of the work. It is also necessary to take into account the thickness of the product, the power of the device and the required welding depth.

Not only the choice of electrodes plays an important role, but also their correct use. Here you will need not only the skill of the welder, but also the capabilities of the equipment. Different settings are used for different electrodes, and today we will figure out what current is selected for which electrodes.

Current setting depending on the electrode

There are many nuances that affect the current setting for a particular electrode. All of them affect the shape of the seam, its size and quality. Here are the parameters taken into account when selecting a diet:

• rod diameter;
• brand;
• the position in which welding will be carried out;
• polarity;
• number of layers.

If you need a seam with several layers, then the parameters may vary. The parameters of the electrodes selected for welding a certain grade of steel are taken as the initial data.

Often, packages indicate current values ​​for welding only in the lower position. In this case, it will be useful to know that for a vertical position the current decreases by about 20%, and for a ceiling position by 25%. This is necessary so that the metal melts more slowly and does not drain from the seam.

The diameter of the rods is selected in accordance with the thickness of the metal. At the same time, you need to take into account the size of the seam and the welding method.

When welding a surface with a width of 3 - 5 mm, you need to take an electrode with a diameter of 3 - 4 mm. A diameter of 5 mm will be sufficient up to a seam width of 8 mm.

The diameter of the seam and the current you will use are directly proportional.

• with an electrode diameter of 3 mm, we will need a current ranging from 65 to 100 A. This spread depends on the welding position and the type of metal. When using for the first time, it is recommended to set the average value. In this case, it will be 80 A. After this, look at the “behavior” of the electrode itself and the metal, and select the most comfortable currents.
• For 4 mm rods, a current of 120 - 200 A is suitable. This is one of the most common diameters. They can work with both large and small seams.
• 5 mm - electrodes operate at a current of 160 - 250 A. The value depends on the position and metal. The depth of welding also plays a big role here - the greater it is, the greater the current needs to be set. A deep bath - more than half a centimeter - will require maximum power. This means that the operating current will be more than 200 A. If work will be carried out in this mode for a long time, then you need to make sure that you have a high-quality transformer.
• Electrodes 6 - 8 mm, used with a current of 250 A. If you are working with thick material, it can be increased to 300 - 350 A.

Setting a low current will result in you not being able to make a connection, since the metal will not weld well. If the current is too high, the metal will melt through.

Recently, low-power devices have been gaining popularity. They are used in the household. They allow you to work with electrodes of small diameter - up to 2 mm.

AC and DC current

First, let's figure out what alternating current is and what is direct current.

AC current changes over time. In a normal network it has a frequency of 50 Hz. This means that when the device is connected to a household network, it will output current with a frequency of the same 50 Hz.

Direct current is obtained using rectifiers and stabilizers. It can have direct or reverse polarity. The advantages of direct current are as follows:

• high stability of the arc, making the seam smooth and reliable;
• high performance;
• a small amount of spatter, which saves material and protects the welder from burns.

Some types of work require the use of only alternating current.

Alternating current is suitable for working with refractory materials containing oxides. It is used when welding aluminum, since the reverse movement of electrons destroys the oxide film. The same applies to contaminated surfaces.

Devices that produce alternating current are used where high quality and precision of the seam is not required, but it is necessary to reduce costs.

When assembling durable and reliable structures, it is better to use direct current. It is also used when working with structures and parts of small thickness.

Conclusion

Correct current setting plays an important role in the work of welders. All recommendations for the use of specific electrodes can be found on the packaging. You need to find the exact settings “for yourself” yourself. With experience, this will become increasingly easier.

Source: http://instrument-blog.ru/svarka/regulirovka-svarochnogo-toka-pod-elektrod.html

How to make a current regulator for a welding machine with your own hands

One of the main components of a truly high-quality seam is the correct and precise adjustment of the welding current in accordance with the task at hand.

Experienced welders often have to work with metal of different thicknesses, and sometimes the standard min/max adjustment is not enough for proper work. In such cases, there is a need for multi-stage current regulation, accurate to the nearest ampere.

This problem can be easily solved by connecting an additional device to the circuit - a current regulator.

The current can be adjusted in the secondary (secondary winding) and in the primary (primary winding). Moreover, each method of setting up a transformer for welding has its own characteristics that are important to consider. In this article we will tell you how to regulate the current in welding machines, provide diagrams of regulators for a semi-automatic welding machine, and help you choose the right welding current regulator for the primary winding for a welding transformer.

How to adjust the current of a welding machine? Thyristor welding current regulators circuits

Schemes Thyristor welding current regulators circuits

One of the main components of a truly high-quality seam is the correct and precise adjustment of the welding current in accordance with the task at hand.

Experienced welders often have to work with metal of different thicknesses, and sometimes the standard min/max adjustment is not enough for proper work. In such cases, there is a need for multi-stage current regulation, accurate to the nearest ampere.

This problem can be easily solved by connecting an additional device to the circuit - a current regulator.

The current can be adjusted in the secondary (secondary winding) and in the primary (primary winding). Moreover, each method of setting up a transformer for welding has its own characteristics that are important to consider. In this article we will tell you how to regulate the current in welding machines, provide diagrams of regulators for a semi-automatic welding machine, and help you choose the right welding current regulator for the primary winding for a welding transformer.

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Methods for adjusting welding current

The quality of the weld depends largely on the characteristics of the electric arc. For each thickness of metal, depending on its type, a certain strength of welding current is required.

In addition, the current-voltage characteristic of the welding machine is important; the quality of the electric arc depends on it. Cutting metal also requires its own electric current values. That is, any welding machine must have a regulator that controls the welding power.

Semiconductor devices

The creation of powerful semiconductor devices capable of operating with high currents and voltages has made it possible to develop a new type of welding machines.

They have become capable of changing not only the resistance of the secondary circuit and phase, but also changing the frequency of the current and its shape, which also affects the characteristics of the welding arc. A traditional transformer welding machine uses a welding current regulator based on a thyristor circuit.

Adjustment in inverters

Welding inverters are the most modern devices for electric arc welding. The use of powerful semiconductor rectifiers at the input of the device and the subsequent transformation of alternating current into direct current, and then into high-frequency alternating current, made it possible to create devices that are compact and powerful at the same time.

In inverter devices, the main regulator is changing the frequency of the master generator. For the same transformer size, the conversion power directly depends on the frequency of the input voltage.

The lower the frequency, the less power is transferred to the secondary winding. The adjustment resistor knob is displayed on the front panel of the inverter. When it rotates, the characteristics of the master oscillator change, which leads to a change in the switching mode of the power transistors. The result is the required welding current.

When using inverter semi-automatic welding machines, the settings are the same as when using manual welding.

In addition to external regulators, the inverter control unit contains many different control elements and protections that ensure a stable arc and safe operation. For a novice welder, the best choice would be an inverter welding machine .

Application of thyristor and triac circuits

After the creation of powerful thyristors and triacs, they began to be used in output current regulators in welding machines. They can be installed in the primary winding of the transformer or in the secondary winding. The essence of their work is as follows.

The control contact of the thyristor receives a signal from the regulator circuit that opens the semiconductor. The duration of the signal can vary within wide limits, from 0 to the duration of the half-cycle of the current flowing through the thyristor.

The control signal is synchronized with the regulated current. Changing the signal duration causes the beginning of each half-cycle of the welding current sinusoid to be cut off. The duty cycle increases, as a result the average current decreases. Transformers are very sensitive to such control.

This regulator has a significant drawback. The time of zero values ​​increases, which leads to uneven arc and its unauthorized extinguishing.

To reduce the negative effect, it is additionally necessary to introduce chokes, which cause a phase shift between current and voltage. In modern devices this method is practically not used.

Source: https://svaring.com/welding/prinadlezhnosti/reguljator-svarochnogo-toka