Soldering iron resistance 12 volts. Homemade miniature low voltage soldering iron

A soldering iron is an attribute of any radio amateur, from a professional to those who have just started. Today on sale you can find soldering irons or even soldering stations of any size. But they all have one big minus - they are quite rough and they have a large distance from the end of the sting to the edge of the handle. Such dimensions are convenient when soldering large parts, but when working with small elements, such devices are inconvenient, due to the fact that they are very heavy. position. Having looked through the schemes of miniature soldering irons on the Internet, I found that many of them have some design flaws: a non-replaceable tip, lack of grounding, and much more. So I decided to try to create more modernized“assistant” for a beginner radio amateur based on several instructions. The features of our future soldering iron include: a small distance from the end of the tip to the edge of the handle (~ 30 -40 mm), handle diameter (~ 15 mm), the ability to replace the tip and heating elements (reserve), ease of manufacture, which does not require any special knowledge.

Homemade miniature low-voltage soldering iron - drawing

As a handle, an ordinary brush was used, which was preliminarily polished and lacquered.
For a good fastening of the wires in the handle, I used such a homemade knot: I made a thread in a hollow rivet and glued it into the handle. Here you can easily fix the cable using the locking screw.
Then I moved on to the manufacture of mounts for the heat shield. They were also made from hollow rivets, but with a smaller diameter. M1.6 thread was created in them and glued into the handle holes.

The heating element was taken from an ordinary inexpensive Chinese soldering iron, after some manipulations with the dimensions, it fit perfectly with our device.

This element has a power of 7 watts and a length of 6.5 mm. Power is supplied by an adjustable power supply unit - from 0 ... 18 Volts. At the same time, the heating temperature can reach 280 degrees.
In the back of the pen was glued a regular spring, which can be borrowed from a regular ballpoint pen. This part is necessary to protect the power cable from breaking.
The ground and power wire is threaded in cambric. A socket for grounding is pressed into the main opening of the plug, which is designed for the cable, and the power cables are led out through an additional hole.
As you can see in the picture, the resulting home-made miniature low-voltage soldering iron in its dimensions barely casts from an ordinary fountain pen.

A tool such as a soldering iron is indispensable for radio amateurs, but people who are far from electronic technology and components do not consider it a necessity. Sometimes situations happen that can only be corrected with the help of this tool, and if it is not there, then what to do? If the problem is one-time, then there is no need to go to the nearest store and purchase an expensive product. You can make a little effort and, with the help of simple components, assemble a homemade soldering iron. There are many options for assembling this device - consider some of them.

Resistor device.

This is a very simple but extremely reliable device. At home, it can be used in different ways. Depending on the design and power, they can solder microelectronics up to laptops. A large device even allows you to solder a tank or any other large product. Consider how to make a soldering iron with your own hands.

The circuit is interesting in that a resistor suitable for power is used as a heater. It can be PE or PEV. The heater is powered from the household network. These quenching resistances make it possible to solve problems of various scales.

We carry out calculations

Before proceeding to the assembly, some calculations should be performed. So, for the manufacture of devices with resistors, it is enough to recall Ohm's law from a school physics course and the power formula.

For example, you have a suitable part of the PEVZO type with a nominal value of 100 ohms. You are going to create a tool based on it for use in household electrical networks. With the help of the form you can easily calculate the parameters. So, at a current of 2.2 A, a homemade soldering iron will consume 484 watts of power. This is a lot. Therefore, with the help of resistance-damping elements, it is necessary to reduce the current by a factor of four. After that, the indicator will decrease to 0.55 A. The voltage across our resistor will be within 55 V, and in the home network - 220 V. The value of the quenching resistance should be 300 Ohms. As this element, a capacitor for voltage up to 300 V is suitable. Its capacitance should be 10 microfarads.

Soldering iron 220V: assembly

Perhaps the glue will worsen the heat transfer a little, but it will dampen the system of the rod and the heating coil. This will protect the ceramic base of the resistor from possible cracks.

Another layer of glue will protect against backlash in this important knot. The cores of the wires will be brought out through the hole in the tube-rod. This diagram will help you understand how to make a soldering iron reliable, efficient and inexpensive, as well as safe.

To avoid trouble, it is better to strengthen the insulation where the cores will be connected to the heater. For this, an asbestos thread is suitable, as well as a ceramic sleeve on the body. Additionally, you can apply elastic rubber in the place where the electric cord enters the handle.

It's so easy to make a soldering iron with your own hands. Its power may vary. To do this, you simply need to replace the capacitor in the circuit.

mini soldering iron

This is another simple circuit. With this tool, you can work with various miniature devices or parts. With it, you can easily dismantle and solder small radio components and microcontrollers. Each craftsman has the materials to create this product. You will learn how to make a soldering iron, and then you can easily assemble it from improvised materials. Power will be provided from a household transformer - any one from the frame scan of an old TV will do. A piece of 1.5 mm copper wire is used as a sting. A 30 mm piece is simply inserted into a heating element.

We make a base tube

It will not be just a tube, but the base of the heating element. It can be rolled up from copper foil. Then it is covered with a thin layer of a special electrical insulating compound. This composition is also very simple and easy to make. It is enough to mix talc and silicate glue, lubricate the tube and dry it over gas.

Making a heater

In order for our do-it-yourself soldering iron to adequately perform its functions, you need to wind a heater for it. We will do this from a piece of nichrome wire. To solve the problem, we take 350 mm of material 0.2 mm thick and wind it around the prepared tube. When you wind the wire, lay the turns very tightly together. Don't forget to leave straight ends. After winding, grease the spiral with a mixture of talc and glue and let it dry until it is completely baked.

We complete the project

The third stage is additional insulation and installation of the heater in a tin case.

This work must be done very carefully. The ends that come out of our heater should also be treated with insulating material. In addition, treat with a mixture of any cavities that may have arisen from a lack of accuracy.

The manufacturing process of this tool involves protecting the heater leads with heat-resistant insulating material and pulling the cord through the hole in the soldering iron handle. Screw the ends of the power wire to the heater terminals, then carefully insulate everything.

It remains to pack the heating element in a tin case, and then evenly put it in place.

Now you can use this product. If you did everything right, you get an excellent soldering iron, assembled with your own hands. With it, you can solder many interesting circuits.

Miniature non-wire resistor design

This tool is great for small jobs. It is very convenient to solder various microcircuits, SMD parts with it. The scheme of the product is simple, with the assembly there will be no difficulties.

We need an MLT type resistor from 8 to 12 ohms. The power dissipation should be up to 0.75 watts. Also pick up a suitable case from an automatic pen, a copper wire with a cross section of 1 mm, a piece of steel wire 0.75 mm thick, a piece of textolite, a wire with heat-resistant insulation.

Before assembling this soldering iron with your own hands, peel off the paint from the resistor body.

This is easily done with a knife or liquid with acetone. Now you can safely cut off one of the resistor leads. Where the cut was made, drill a hole, and then process it with a countersink. A sting will be mounted there.

At the very beginning, the hole diameter can be equal to 1 mm. After processing it with a countersink, the sting should not come into contact with the cup. It should be in the resistor housing. Make a special groove on the outside of the cup. A down conductor will be held on it, which will also hold the heater.

Now we make a payment. It will consist of three small parts.

From the wide side, connect a steel down conductor to it, in the middle part the case from the handle will be fixed. The second remaining output of the resistor is installed on the narrow part.

Before using this tool, wrap the tip with a thin layer of insulating material. That's how simple and easy you got a low-power 40W mini soldering iron.

Naturally, serious and hot-air hair dryers are offered today for professionals, but these devices are very expensive and are available only for masters from service centers for repairing computers, laptops and mobile devices. This equipment is inaccessible to the home master due to its cost. We hope this article will tell you how to make a soldering iron with your own hands quickly and easily.

Sometimes there are situations when the owner simply cannot do without a simple soldering iron. For example, you need a multi-core cable for an outlet, or from a burned-out appliance. At such moments, one has to either borrow an instrument, or postpone the matter for an indefinite period. After all, not everyone wants to buy an expensive soldering iron or soldering station if he is not a repairman. However, there is a simple way out of this situation - to independently assemble a small soldering iron, it is just right for small work. The manufacturing process will not take much time and effort, but you can save some money and gain invaluable experience. Next, we will tell you how to make a soldering iron with your own hands at home. You will be offered several designs, and you can choose the one that suits you the most.

Idea #1 - Use a Resistor

The first and most simple technology for making an electric soldering iron with your own hands is using a powerful resistor. The device will be designed to operate at a voltage of 6 to 24 volts, which will allow it to be powered from various current sources, and even make a portable version powered by car battery. In order to make your own tool, you will need the following materials:

To make a soldering iron from a resistor at home, you must follow these steps:

1. At the end of a thick copper rod, you need to drill a hole and drive the thread under the screw with a tap. It is also necessary to cut a groove for the retainer, which in our case is the spring ring. This can be done with a triangular needle file or a hacksaw.
   
   
2. From the second end, drill a hole with a diameter like a thin rod, which will act as a mini soldering iron tip.
3. All elements of the rod must be assembled into one whole, as shown in the photo.
   
4. The resistor is prepared for mounting the soldering iron tip, which must be inserted and fixed at the back with a screw with a washer.
   
5. From a textolite or plywood plate, you need to make a comfortable handle with a seat for a resistor and a wire with your own hands. To do this, use a jigsaw to cut out two identical halves of the handle and make holes and recesses for screws and nuts.
   
   
6. Connect the power cord to the heater terminals. It must be screwed onto the screws so that the contact is reliable.
   
7. The finished homemade soldering iron is twisted and checked.
   

We draw your attention to the fact that with such a portable gun you can easily solder microcircuits and even with your own hands. It can work not only from the power supply, but also from the battery. On the forums, we met a lot of reviews, where this homemade version was connected from a 12 volt cigarette lighter, it is also very convenient!

Please note that when first turned on, all soldering irons may smoke and stink for a while. This is normal for any model, as some elements of the paintwork will burn out. This will stop later.

Video instructions for making a simple electrical appliance

Idea number 2 - The second life of a ballpoint pen

There is another unusual, but at the same time simple idea of ​​how to make a soldering iron with your own hands from improvised materials for soldering small parts or smd components. In this case, again, it will come in handy for us, but now it’s not PEV (as in the previous version), but MLT, with a power of 0.5 to 2 watts.

So, first you need to prepare the following materials:

• Ballpoint pen of the simplest design.
• Resistor with characteristics: resistance 10 Ohm, power 0.5 W.
• Double-sided textolite.
• Copper wire with a diameter of 1 mm, it can be wound from an old choke or you can buy a single-core copper wire in insulation at an electrician's store and carefully remove it with a clerical knife
• Steel or copper wire with a diameter of not more than 0.8 mm.
• Wires for connecting to the network.

Making a soldering iron from a pen at home is quite simple, you just need to follow these steps:

1. Remove a layer of paint from the surface of the resistor. This operation can be carried out with the help of a skin, a needle file or a file, in extreme cases, a knife. The main thing is not to overdo it, so as not to damage the resistor. If the paint is difficult to remove, connect the product to a regulated power supply and heat it up a little.
2. 2 wires come out of the barrel, cut one of them and drill a hole for a copper wire in this place (diameter 1 mm). To prevent the wire from touching the cup (this must be avoided), countersink with a thicker drill, as shown in the photo below. In addition, you need to make a small cut for the wire right on the resistor cup. A triangular file will help you with this again.
   
3. Bend the steel wire into the shape of a ring-shaped handle, with a diameter similar to that of a drank on a cup. If you have copper wire, then you need to clamp the cup in it and twist it with pliers so that the contact is reliable, but do not overdo it, otherwise you will wrinkle the case. Remember that the wire must be without varnish insulation.
   
4. Carefully cut out the board from the double-sided PCB with your own hands, exactly the same as shown in the example in the photo. It is not necessary to buy a new sheet of textolite. You can use a jigsaw to cut a suitable piece from any unnecessary double-sided board. Or do without it altogether: twist the wire with wires, and attach them to the handle with superglue. The main thing to pay attention to is that the distance between the heating element and the handle is more than 5 cm, otherwise the plastic may melt.
   
   
5. Next, you need to assemble a homemade soldering iron from the handle, which should not cause difficulties.
   
6. It remains to install a thin sting in the seat. To prevent the copper wire from burning through the resistor, you need to make a protective layer of a piece of mica or ceramic between the back wall and the sting.
   
7. The last thing to do is to connect the homemade product to a 1 A power supply and a voltage of no more than 15 Volts using wires.
   

That's the whole technology of creating a homemade mini soldering iron at home. As you can see, there is nothing complicated in making this tool, and you can easily cope with it, and all the materials can be found at home by dismantling old equipment or looking for them in the bins.

How to make a more complex model of a mini soldering iron at home?

Video review of a device with nichrome wire, powered by 12 volts

Idea #3 - Powerful Impulse Pattern

This option is suitable for those who are already more or less familiar with radio engineering and can read the corresponding diagrams. A master class on making a homemade pulsed soldering iron will be provided following the example of this scheme:

The advantage of this tool is that the tip heats up within 5 seconds after turning on the power, while the heated rod can easily melt the tin. At the same time, it can be made from impulse block lamp power daylight, slightly improving the board at home.

As in the previous examples, we will first consider the materials from which you can make a soldering iron with your own hands at home. Before assembly, you must prepare the following improvised means:

All you need is to connect the tip to the secondary winding, which, in fact, is already part of it. After that, one of the ballast leads must be connected to the primary winding of the transformer and all the elements of the circuit must be fixed in a reliable case that will protect you from accidental electric shock, since the circuit contains a life-threatening voltage of 220 volts!

The principle of operation of this design is that the ballast from the lamp creates an alternating voltage that is applied to the primary winding of the transformer and is reduced to low values, while the current increases many times over. One turn, which is, in fact, the tip of the soldering iron, acts as a resistor, on which heat is dissipated. When the button is pressed, current is supplied to the circuit, and rapid heating occurs, after the button is released, the tip cools quickly, which is very convenient, since you do not have to wait long for the tool to heat up and cool down.

For soldering electronic circuits, special care must often be taken when heating the leads of semiconductor elements. They are very sensitive to temperature.

In addition, sometimes when debugging a circuit, you have to solder with the power connected. In this case, using a conventional soldering iron powered by a 220 volt network is dangerous. For such cases, it is better to use an electric soldering iron that operates on a voltage of 12 volts.

A 12 volt soldering iron can operate on both AC and DC.

A soldering iron operating on direct current can even be connected to the vehicle's on-board network, provided that its power does not exceed the calculated power of the car's electrical wiring.

There are many designs of soldering irons on the market that use low voltage. You can distinguish them by the obligatory inscription on the case, on the packaging.

This voltage must be indicated in technical specifications tool. If you have an unnecessary soldering iron for 220 volts, you can make a 12 volt one yourself.

Alteration of an old soldering iron

In order to remake a standard soldering iron, you need to disassemble it, remove the heating element. Instead, a nichrome thread with a thickness of 0.02-0.20 mm should be wound on a mica substrate. The thread can be removed from any used electrical appliance, such as a hair dryer.

The length of the thread is selected experimentally depending on the thickness and the required degree of heating of the soldering iron. When winding the thread, it is necessary to ensure that the turns do not touch each other.

The sequence of work is as follows:

• after selecting the length of the wire, the turns are fixed with some heat-resistant glue;
• the thread at both ends is connected by wires to a power source. It can be a 12 volt converter, a power tool battery, or a car battery;
• the case of a new 12 volt soldering iron must be assembled and it will not differ in any way from the previous one.

In order not to accidentally turn on the tool in a 220 volt network, it is recommended to make a catchy, clearly visible inscription on the handle - “12v”.

From a resistor

You can make a miniature homemade 12 volt soldering iron using fixed metal film resistors, for example, a 2 W MLT-2.

They work even with an overload up to 6-10 times, so it is easy to get power from them up to 12-20 watts. But a significant part of it will be wasted on heat exchange with air due to the relatively large surface area of ​​the resistor. For manufacturing, you need a resistor with a nominal value of 24-27 ohms.

One of its fairly thick leads will serve as a soldering iron tip, the second as a contact for the power wire.

The resistor case near the contact-sting must be cleaned of paint and tightly wrapped with a second supply wire. The working scheme of the soldering iron is ready.

It remains only to place it in a case that will be convenient to use. To do this, the resistor is wrapped with a heat-resistant heat-insulating material, for example, fiberglass, and placed in a plastic tube of a suitable diameter.

Use in the car

In modern cars, there are few such components and parts that can be repaired independently, outside the garage or workshop. Most likely, it can be damaged wire harnesses at the folds.

Such malfunctions are easy to fix right on the road. It is enough to remove excess insulation and twist the wires, then protecting the twist with insulating tape.

But the wiring of the car works in very difficult conditions. It is subject to vibrations, frequent changes in temperature and humidity, especially in winter.

Under such conditions, the twisted contact may be lost, and when using a conventional single-wire electrical circuit loss of contact can have an unpredictable effect on the behavior of the car.

To prevent this undesirable phenomenon, it is recommended to solder the twist. To do this, you will need a car soldering iron powered by a cigarette lighter.

Almost all car cigarette lighters are powered by a wire line rated for up to 15 A. This is quite enough to connect a soldering iron with a power of up to 100 watts. And more is unlikely to be needed. They also remake the cigarette lighter itself into a palnik. It turns out a miniature infrared hair dryer.

In older cars, soldering may be needed to repair relay and fuse mounting blocks, to solder terminals to wires broken during use.

The purpose of the soldering iron is known even to people far from electricians. It is not at all necessary to talk about those who work in this area - for them it is simply an indispensable assistant. And the market, taking this into account, provides a huge number of devices that differ in many parameters. But not in all cases it is advisable to spend money, because you can make a full-fledged soldering iron with your own hands, without having any specific knowledge.

Homemade soldering iron

It makes sense to buy a soldering iron if you have to work with them constantly, or at least quite often. But if this is a tool that gathers dust on the shelf most of the time, then there is not much point in spending money. Moreover, it is quite possible to independently make a full-fledged apparatus of the necessary power, taking into account the likely needs.

Of course, in order to know how to make a soldering iron with your own hands, you need to understand its structure and principle of operation. After all, despite the external simplicity, there are some nuances that are preferable to know before starting work.

Structure and principle of operation

Soldering irons have an extremely simple device: a copper rod that interacts with a heating element is placed in a kind of tube that acts as a housing. A heat-resistant power cable is connected to the heater. And the whole structure is completed by a handle made of a material with low thermal conductivity.

Under the action of an electric current, a heating element (for example, a nichrome spiral) transmits thermal energy on a copper rod called a sting. The tip, having a high thermal conductivity, heats up, which allows soldering.

Knowing how the soldering iron works, it is quite possible to make it yourself. And to implement this idea different ways taking into account the needs of a particular situation.

Soldering iron for 220 volts on a resistor

The option with a voltage of 220 V, first of all, is good because it does not require a search for a power supply. At the same time, depending on the specific needs, its power can be made different, which allows you to create an electric soldering iron with your own hands both for soldering small equipment, and a hammer soldering iron for sealing tanks, pans and other metal utensils.

First you need to prepare parts that will be required in the process of making a soldering iron:

Depending on what work is expected to be done in the future with a soldering iron, you need to choose its power. And already on the basis of these data it is necessary to carry out calculations.

Here it is worth remembering the school physics course, and in particular the power formula and Ohm's law. To simplify the calculation, it is supposed to take a 100 ohm resistor as an example. Considering that the current will be 2.2 A, when using such a resistor, the soldering iron will consume 484 watts, which, of course, is too much. Therefore, the voltage needs to be reduced. A 300 ohm damping resistor and a 10 uF capacitor to 300 V will help in this. Thus, it will turn out to four times reduce the current, that is, to about 0.5 amperes, which will allow you to get a voltage across the resistor of 55 V.

When necessary calculations completed, you can go directly to the solution of the question of how to make a soldering iron at home, i.e., to its mechanical assembly.

The main thing here is to correctly position the sting in the resistor. In order to securely fix it and reduce the gap between the copper rod and the resistor, fill it with silicate glue. This will also help protect the part from the possibility of cracking during operation.

To reinforce the insulation at the junction of wires and the heating element it is better to additionally wind asbestos thread. It would be useful to use an additional ceramic sleeve for these purposes. All this will make a homemade soldering iron safer and more reliable.

Now it remains to place the resulting structure in a suitable iron tube, on which a handle made of wood or textolite is mounted. A wire is passed into the hole of the handle as in a classic soldering iron to connect to the power supply.

Low power mini soldering iron

Quite often, the use of powerful models is inconvenient and impractical. This is especially true for work carried out during the repair of small household appliances, soldering smd and other elements sensitive to high temperatures. In such cases, a low-voltage, small, light and convenient soldering iron with a thin tip will come in handy. And here it would be useful to know how to make a mini soldering iron with your own hands, because the estimated costs in this case will be much less than in the case of buying a factory model.

As usual, it all starts with the preparation of parts and parts that will be required in the process.

• Copper wire with a diameter of about 1 mm.
• An unnecessary ballpoint pen that acts as a case.
• A small piece of textolite measuring 30 by 10 millimeters.
• A little steel wire with a diameter of 0.8 millimeters.
• Since the soldering iron is made of a resistor, a 5-10 ohm resistor is used.

The first step is to prepare the resistor itself. To do this, you need to clean it from paint. You can do this in different ways: just scrape it off with a knife, connect the power and let it warm up, then remove the paint or wipe it off with a solvent. After that, one of the legs is removed, and in this place a hole is carefully drilled with a 1 mm drill, just enough for the prepared copper wire to enter. Wherein Special attention it is worth paying attention to the fact that it does not touch the body of the resistor. Therefore, it is worth processing the hole with a slightly larger drill - countersinking.

On the processed side of the resistor, on the cup itself, a small cut is made, where the current lead loop should subsequently lie. It is also made of steel wire, bent in such a way that a loop is obtained, which will lie in the sawn groove-propyl.

Now a piece of textolite is taken, which is cut out in such a way that one end fits well into the body of a ballpoint pen. Here, contacts are soldered on both sides, to which the supply wires will subsequently be connected. The other side of the textolite plate is made a little wider so as not to enter the pen body. Contacts are also soldered here, to which current-carrying parts from the resistor will be connected. Externally, the resulting blank resembles a kind of letter "T" approximately as in the figure:

Now all the details need to be collected. A wire with a loop is placed in the corresponding groove on the transistor, its ends are soldered to the contacts on the textolite plate.

A copper sting is inserted into the hole of the transistor. In this case, it would be useful to make protection from mica or a similar material so that during the heating of the sting, the resistor itself would not be damaged.

Wires are passed into the body from a ballpoint pen, which are soldered to the contacts on the thin side of the textolite plate - this will be the power. After that, the plate itself is also placed in the handle body.

When the base of the soldering iron is assembled from a resistor with your own hands, you should think about power. For this, a power supply with a voltage of up to 15 volts is suitable. Although it is best to use 9–12 V, this is the optimal voltage for the operation of such a device.

As you can see, with a minimum amount of materials that can easily be found in almost every home, you can make an excellent and safe homemade 12 volt soldering iron without having a high knowledge of electrical and electronics.

Autonomous battery powered device

Those who often have to work "in the field" know that the presence of an outlet where you can connect a stationary soldering iron is far from always the case. Therefore, it will be useful to have an autonomous tax in reserve. Of course, it will not work to produce soldering that requires a powerful model, but such a micro-soldering iron is still able to perform most of the work. Therefore, it is quite advisable to make a battery soldering iron with your own hands in order to simplify the work in some cases.

Almost all the parts that make up the cordless soldering iron model can be found in almost every home. Therefore, before starting work, you need to prepare:

When everything is ready, you can proceed directly to the assembly of the soldering iron. And first you need to make a heating element: a nichrome thread must be wound on a prepared copper wire with a diameter of 2 mm in the form of a spiral. In this case, the length will have to be determined empirically. So, the heating of the spiral should reach a temperature of 300 to 450 degrees Celsius.

Now you need to put a piece of a heat-resistant tube on the same wire and wind a measured nichrome thread on it. Smaller tubes are put on its ends, after which a tube of the largest diameter is put on the entire resulting structure. Now the copper wire inside can be carefully removed.

The resulting heating element remains to be placed in a piece of antenna cut off to a suitable size. A sting is also inserted here and fixed with a self-tapping screw.

In general, the whole base is already ready. It remains only to solder the wires for power to the spiral and place everything in the case.

In order to prevent fire, between the tube with the heating element and the housing it is necessary to insert a piece of some non-combustible material.

The result is a cheap, reliable and convenient tool for soldering in the field.