How to assemble a soldering iron from 12 v. Do-it-yourself soldering iron at home in different ways. PEV resistor resistance for soldering iron

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 by various current sources, and even make a portable version powered by a 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 a switching power supply from a fluorescent lamp, 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.

At 12 volts - a necessary tool for modern radio electronics in the home. With it, you can quickly solder microcircuits, parts of an earpiece, electronic wristwatches, and repair your phone charger. Many radio amateurs prefer to make an electric soldering iron with their own hands. This work saves money and does not let you forget the school physics course.

Necessary materials and tools

You don’t need much material to make a soldering iron, and you can easily find it at home. These are copper wire for the manufacture of a directly soldering base, copper foil, a tin tube (for a casing) and nichrome wire, a handle (preferably plastic), an electrical cord in heat-resistant insulation, silicate glue, talc for electrical insulating mass.

Sometimes it's hard to find copper foil. You can use foil fiberglass. It is often used in the manufacture of printed circuits and circuit boards. If there are no such houses, you can contact the store and purchase the necessary material for 200 rubles. To get one sheet of copper foil, you need to heat the fiberglass with an ordinary iron and, dividing it into thin plates, pull the corner, wind it around a round stick.

The main element is a 220/12 volt transformer, through which the soldering iron will receive energy from the mains. TVK-11OL is often used. It can be found in old tube TVs.

Required following tools:

• tweezers;
• pliers;
• wire cutters;
• plates or boards for coating with adhesive mass;
• stove (electric or gas);
• rag.

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Soldering iron assembly steps

The copper wire you purchased will serve as the tip of the micro soldering iron. It will take only 50 mm. It must be sharpened in the form of a dihedral angle on one side and be sure to tin the edges. The finished sting will be inside the heating element.

The second stage in the manufacture of a microsoldering iron will be the preparation of a special electrical insulating mass. To do this, mix talc and liquid glass (silicate glue). Using a board or tweezers, apply insulation to the cylindrical surface, periodically sprinkling with talcum powder so that the mass does not stick to your hands.

Roll the copper foil into a tube about 35 mm long. This will be the base of the heating element. On one side, a soldering iron tip will be visible from under the tube. This tube must be covered with an insulating mass, as in the first case. The raw mass that you applied must be dried over the stove until completely solidified. Now you can wind the nichrome wire on the finished base by making a spiral. Its length should not exceed 350 mm. The turns must be laid carefully and very close to each other, while the upper and lower ends of the wire (from 30 to 60 mm) are left as conclusions. This structure is once again covered with a mixture of electrical insulation and dried over the stove.

Now the bar end of the wire must be bent back, pressed firmly against the surface of the tube and repeated applying the mass a third time. Only after that the heating element of the soldering iron can be considered completely ready for use.

The wire that protrudes from under the heating element must be covered with an electrical insulating mass. At the same time, you need to be patient and, each time applying a lot, do not forget to check the quality of the actions performed.

When the base is completely covered with insulation, you can start assembling the microsoldering iron. We connect the ends of the nichrome heater with a handle. To do this, we stretch an electric cord in heat-resistant insulation through the internal plastic cavity. Bare spots should be isolated with mass and dried. After that, we put a protective tin casing on the heater and connect it to the handle. The micro soldering iron is ready for use.

If for the beautiful half of humanity the word soldering iron is an empty meaningless object, then for men it is a device that saves them in any life situation, especially when carrying out simple repairs with radio electronics. Is it possible to make a 12 volt soldering iron with your own hands at home. If you are a little friendly with physics and you have the title of "jack of all trades", then assembling the simplest primitive low-voltage soldering iron will be within your power. Let's take a look at one of the few options available to any of you.

Homemade 12 volt soldering iron

Materials and tools needed for self-assembly of a low-voltage soldering iron

To make a soldering iron with your own hands at home, you will need to prepare a certain set of tools and materials, in particular:

• Wire made of copper material, wire diameter 1.5 mm, length - no more than 40 mm.
• Foil, preferably copper, 10 * 30 mm in size, a little more.
• Nichrome wire 0.2 mm thick, length no more than 350 mm.
• A piece of tin or any round metal pipe (necessary for the manufacture of the casing structure) will be required for the heating element.
• Silicate glue or good liquid glass.
• For the manufacture of an insulating layer, talc is needed, which is diluted with silicate glue.
• Handle, preferably of insulating plastic material.
• Standard electrical cord with plug.

Soldering iron for 12 volts from the cigarette lighter

In addition, when creating a 12-volt soldering iron from the cigarette lighter with your own hands, you will need additional items and things, without which the assembly of the device will be incomplete:

• A constant source of heat is an electric or gas stove.
• Locksmith's tools - pliers, wire cutters, tweezers, needle files, files.
• A non-standard fixture, somewhat reminiscent of a small spatula, preferably made of wood or durable plastic.
• Rags, in the process of work, you will have to remove a lot of dirt and often.

In principle, this is the main set of materials and tools needed to make a 12-volt soldering iron with your own hands from a resistor.

The procedure for assembling the soldering iron

You have prepared the tools and materials! Now it remains to follow the approximate procedure, and then you can assemble a homemade 12 volt soldering iron without much difficulty.

• We take copper wire and make a sting. Note that one end of the wire must be sharpened at an angle of 45 degrees. Although this requirement is optional, it is still better to sharpen one end of the working copper wire at any angle. We tin the end of the wire.
• We knead the working insulating mass based on talc and silicate glue. The main thing is to achieve a pasty form of the substance. Remember, all this time you will have to deal with sticky hands, while sprinkling powder and wiping your hands with rags.
• The finished sting must be tightly wrapped in copper foil, while leaving about 10 mm of the structure completely free.
• Sprinkle a talc-based insulating material on top of the copper foil structure. In this case, you will have to use a heat source to dry. The heating temperature should be from 100 to 150 degrees.
• We take a nichrome thread, we wind the spiral design. All turns should be applied as tightly as possible, while one end of the turn should have a free size of 30 mm (so-called straight turn), and the second turn - 60 mm (conditional size of the turning turn).
• We cover the winding with an electrically insulating working mixture. In the same way, it is necessary to dry it on a heat source - a gas or electric oven.
• We put the finished long end into the tube, but in this way keeping the distance at the maximum size between it and the straight one, while the approximate distance will be the diameter of the structure. After that, additional coating and an additional baking workflow will be required.
• Now the tip mounted in the tube is ready as a full-fledged heating element.
• You are left with the remains of nichrome wire sticking out at both ends. Similarly, we process with a similar insulating composition to about half the size. We dry the wire over the oven. We control so that the remains of the processing sites are completely covered with an insulating compound. In some cases, this process will have to be done several times, but for safety reasons, it is best to completely isolate the remains of the nichrome thread.
• We assemble the body of the soldering iron. We stretch the working cord through the hole in the handle. We make a connection from the ends of the raw nichrome with the bare parts of the cord. After that, we isolate the junctions of talc with synthetic glue according to a proven technology from above.
• We put on a casing on the prepared heating element. One working end of the casing should be technologically included in the design of the handle, the second casing component is recommended to be fixed with metal devices, in the form of a cap with holes, which should completely exclude contact contact, with the copper filling of the built-in component of our heating device. If necessary, you can limit yourself to only a clamp.

The device is ready, it is necessary to test it correctly!

Very important! The soldering iron can only be connected to the network through a 12 Volt transformer or through a 12 Volt power supply, while the current strength is not more than 1 A.

What you need to know more about the 12 volt soldering iron

The soldering iron is completely ready for work, it can be used to work on connecting sections of boards with microcircuits. Care must be taken to minimize the effects of static electricity.

As a rule, this is an alternative version of the device for those who consider their budget and want to use the device for simple soldering of microcircuits or other household appliances and assemblies. Resistors can be used as an option. Experts say that despite the abundance of Chinese resistors, it is still better to use Soviet or Russian counterparts, in particular, PEV-10 or PEV-7.5. In this case, you will have to leave the sting, which is fixed in the working position in a copper-type tube. In this case, the working element of the tip must be tightly pressed into the resistor housing. In addition, you will also need to fix the contacts of the resistors, which in certain situations will not be able to withstand complex mechanical loads.

Scheme of assembling a soldering iron from a resistor

There are additional assembly options for soldering irons that have the ability to operate at low voltage. Be sure to use insulating components and parts that you use when assembling the soldering iron with your own hands.

Before starting work, we recommend testing the device, while observing electrical and fire safety. After testing, try the device in action on simple microcircuits. Be sure to pay attention to the metal parts, which must be properly insulated.

Homemade micro-soldering irons are not intended for industrial production. Use devices only for domestic and household work!

Homemade miniature 12 volt soldering iron for electronics enthusiasts

We offer you, as an option, to make a miniature electric soldering iron for 12 volts from available materials using available equipment. It will be very convenient for working with small-sized working material - when soldering the leads of various microcircuits, parts of micro-earphones, hand-held electronic watches (or, for example, making USB itself - charging for a cell phone) and any other miniature elements of modern radio electronics.

Homemade microelectrosoldering iron

The set of materials required for the product is quite small. You will need: copper wire for the soldering iron tip; copper foil, nichrome wire and a tin tube - a casing for an electric heater; plastic heat-resistant handle; electric cord in heat-resistant insulation; office silicate glue and talc for electrical insulating mass.

It is possible that you will have some problem with copper foil. But she's completely doable. If there is no foil, then it is not difficult to find foil fiberglass, from which printed circuits and boards are made (if printed circuits or boards are not lying around anywhere, then fiberglass can be bought for 200 rubles at a radio goods store). You can separate the foil layer from fiberglass by heating it with an iron. It is difficult at the beginning to pry off the edge of the foil, and then after the iron, you will easily wind the foil onto a round stick. In this case, the main thing is to pull the foil evenly.

Necessary equipment: electric or gas stove, tweezers, pliers, wire cutters, plates or boards for coating with adhesive mass, rags for wiping hands and tools.

The miniature soldering iron will be powered from the household power supply through a 220/12 volt step-down transformer, the secondary winding of which should deliver 1 ampere current into a 12-ohm load. Quite suitable, for example, is the TVK-110L transformer used for frame scanning in vintage tube TVs (Record-V300, Vesna-308 and the like). An LCD TV is not suitable for this purpose.

As a soldering iron tip, take a piece of copper wire 40 mm long and 1.5 mm in diameter. Sharpen one end of the wire in the form of a dihedral angle with a solution of 40˚, after which the edges of the angle (“cheeks” of the sting) are tinned. The manufactured sting will be inside the heating element.

Now prepare a special electrical insulating mass: knead talc on office silicate glue (liquid glass) until a thick dough is obtained. With this mass, you will apply thin layers of insulation on a cylindrical surface using any devices (tweezers, planks, plates). Keep in mind that the cooked raw mass is very sticky, and to prevent fingers and tools from sticking, sprinkle them with dry talcum powder from time to time.

Tightly roll a 30 mm tube of copper foil around the sting - the base for the heating element (the end of the 10 mm sting will stick out of it). Carefully cover the tube with a thin layer of electrical insulating compound. Then, holding over a gas or electric burner (the temperature should be 100-150˚), dry until the electrical insulation test is completely “sintered”.

On the prepared base of the heating element, wind a heating coil made of nichrome wire 350 mm long and 0.2 mm in diameter. Lay the coils tightly to each other in one layer. Do not forget to leave straightened ends - wire leads: one - 30 mm long, the other, "bar" - 60 mm. Cover the winding with a protective electrical insulating layer and repeat drying in full.

When the winding insulation is dry, wrap the long ("wrap") end of the wire back and, pressing it firmly against the surface of the tube, apply the third layer of your pasty mass and repeat the drying process again. The heating element of the soldering iron is ready.

Also cover the two ends of the wire protruding from the heating element up to half of their length with electrical insulating mass (the remaining halves will be connected to the wires of the power cord). This operation will require special patience and accuracy from you: often you have to additionally stuff the remaining microcavities due to an oversight or negligence with raw “dough” and dry it over the burner each time.

The final design procedure is the assembly of a microelectrosoldering iron. Through the inner cavity of the plastic heat-resistant handle, pull an electric cord in heat-resistant insulation and screw the ends of your nichrome electric heater to its bare cores.

And finally, the last procedure for coating and drying: insulate the bare places where the electric heater is connected to the electric cord. After that, mount the electric heater in a suitable tin protective casing and connect the casing to the handle.

After a test turn on and warm up, your miniature 12 volt soldering iron will be ready for use.

When working with soldering, any radio amateur will always need a can of compressed air so that you can blow dust off the board. In this article, you will learn how to make such a spray can at home.

Now watch this helpful video:

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12 VOLT SOLDERING IRON

In previous materials, we considered exclusively 220 V soldering irons, and today it's time to review the low-voltage one. According to the S-Line manufacturer's instruction manual, the ZD-20A mini electric soldering iron with a supply voltage of 12 volts and a power of 8 watts is designed for assembly soldering of elements of electronic equipment with tin-lead solders. AC voltage must be used for power supply. Protection class 2, soldering tip operating temperature 250-400 degrees, warm-up time 3-5 minutes. To avoid overheating, it is recommended to turn it off for 15-20 minutes every 3-4 hours of operation to cool down. And finally, in order to avoid death, any repairs should be carried out in a specialized workshop.

I've been eyeing this soldering iron for a long time. Last year, while assembling the power supply, I found a place on the front panel for installing an RCA connector, using a simple “tulip” to connect it. And so, last weekend, deciding that the “bride-in-law” dragged on, he went and bought it. Paid 140 rubles. I must say right away that the packaging with the soldering iron is cute - it's nice to take it in your hands. From the internal contents, this is actually the soldering iron itself and the instruction manual. The instruction is made one at once for the entire range of soldering irons manufactured by the company. The soldering iron has a length of 156 mm, the largest diameter is 16 mm, the tip length is 12 mm, the diameter is 0.5 mm. The plastic handle, in the place of finger grip, is additionally covered with a casing made of low thermal conductivity material. The power supply cable consists of two independent wires in a common PVC sheath. In the hand, it is convenient to hold the soldering iron between the thumb and forefinger, supporting it from below with the middle one, like a fountain pen. It weighs like a helium fountain pen.

The resistance of the heating element spiral that interested me turned out to be 104 ohms.

After connecting to the power supply and setting the voltage to 12 volts, a more interesting parameter became known - current consumption, which amounted to 480 mA. Now you can find out the true power of this particular soldering iron:

P \u003d U x I, P \u003d 12 V x 0.48 A \u003d 5.76 W

Now it will not be superfluous to find out how many degrees in general and in how many minutes the soldering iron tip can heat up.

Within three minutes, the heating of the sting was carried out quite intensively and easily reached the mark of 240 degrees.

• AC voltage recommended
• for soldering smd components this will be quite enough, I will even say that more is not needed
• if necessary, it is worth slightly raising the supply voltage, there will be 270 and 300 degrees.

I installed a plug on the wires of the soldering iron and tried to “get to know” the heating element. The uncomplicated (double “bite” with wire cutters) fastening of the heating element inside the casing unequivocally upset. Further autopsy did not continue. The only identified drawback is the method of attaching the heating element, which will make it difficult to disassemble the soldering iron if it is necessary to repair or modify it.

The soldering iron took its place. There is a handkerchief soldered with a standard-sized soldering iron, it didn’t work out carefully then, I took it out and tested the work of a mini soldering iron on it.

Video

The “movie” scenario is straightforward, the main thing here is different: it is immediately clear that this soldering iron is in place here, the tip of the tip “crawls” everywhere, the component’s view will not obscure, will not overheat it, will not budge. In the attached archive, instructions for soldering irons of the ZD / TLW, WD series. In general, I am satisfied with the purchase, I even got the mood to solder the shown board of the Eldorado metal detector. Previously, I wanted to make a low-voltage soldering iron on my own, but I did the right thing by buying it and I wish you the same, Babay.

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How to make a soldering iron with your own hands

A soldering iron is an empty phrase for many, but for most men it is an indispensable tool in everyday life. And it doesn’t even matter if you are repairing electronics, or just an inquisitive mind does not give rest to your hands. In this article we will talk about creating a soldering iron with your own hands from improvised materials. But we’ll make a reservation right away that it’s easier to buy, it will be more reliable and safer for your health.

1) How to make a soldering iron with your own hands - a schematic diagram of a soldering iron

As you can see, the soldering iron is very simple in terms of design and everything you need to assemble it yourself at home is quite found in every home.

How to make a soldering iron with your own hands - what you need

Our current model soldering iron will run on a 12-14 volt battery. This is much safer than using 220 volts in a homemade soldering iron.

• Li-ion rechargeable battery (quite suitable from a power tool or an old laptop).
• A piece of single-core copper wire with a diameter of about two millimeters and a length of five to six centimeters. We will need it to wind the spiral.
• Heat-resistant fiberglass tubes with different diameters of 3.8 and 1 mm to isolate the heating element from the metal casing (you can take it from an electric kettle).
• Nichrome wire with a diameter of 0.3 mm (you can take it from an old hair dryer). The length of the wire will be selected empirically, depending on the power of the soldering iron and battery.
• A segment of a telescopic antenna from a radio receiver with a diameter of 4 millimeters and a length of 3 centimeters.
• A piece of copper single-core wire for a sting, with a diameter of 3.8 mm.
• Wire for connecting power to the soldering iron.
• Wooden or plastic tube for the handle.

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 also be indicated in the technical specifications of the 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, contact in the twist can be lost, and when using a conventional single-wire electrical circuit, the loss of contact can unpredictably affect 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.

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.