A tool such as a soldering iron is indispensable for radio amateurs, but people who are far from electronic equipment and components do not consider it an essential item. 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 in nature, then there is no need to go to the nearest store and purchase an expensive product. You can put in a little effort and use simple components to assemble homemade soldering iron. There are many options for assembling this device - let's look at 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. The large device even allows you to seal a tank or any other large product. Let's look at how to make a soldering iron with your own hands.
The circuit is interesting in that a resistor of suitable power is used as a heater. It can be PE or PEV. The heater is powered from the household network. These damping resistances make it possible to solve problems of various scales.
We carry out calculations
Before moving on to assembly, there are some calculations you should do. So, to make devices with resistors, it is enough to remember 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 use it to create a tool for use in household electrical networks. Using the form you can easily calculate the parameters. So, at a current of 2.2 A, a homemade soldering iron will consume 484 W of power. That's a lot. Therefore, with the help of resistance-damping elements, it is necessary to reduce the current by four times. After this, the indicator will decrease to 0.55 A. The voltage on our resistor will be within 55 V, and in the home network - 220 V. The damping resistance value should be 300 Ohms. A capacitor for voltages up to 300 V is suitable for this element. Its capacitance should be 10 µF.
Soldering iron 220V: assembly
It is possible that the glue will slightly impair the heat transfer, 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 play in this important node. The wire strands will be brought out through the hole in the rod tube. This diagram will help you understand how to make a soldering iron that is reliable, efficient, inexpensive, and safe.
To avoid troubles, it is better to strengthen the insulation where the conductors will be connected to the heater. An asbestos thread is suitable for this, as well as a ceramic sleeve on the body. Additionally, you can use elastic rubber in the place where the electrical cord enters the handle.
This is how easy it is 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 one simple circuit. This tool can be used to work with various miniature devices or parts. With it, you can easily dismantle and solder small radio components and microcontrollers. Every 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 scrap materials. Power will be provided from a household transformer - any frame scan from an old TV will do. A piece of 1.5 mm copper wire is used as a tip. The 30 mm piece is simply inserted into the heating element.
Making a base tube
This will not be just a tube, but the base of the heating element. It can be rolled from copper foil. Then it is covered with a thin layer of a special electrical insulating composition. 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 DIY soldering iron to adequately perform its functions, we need to wind a heater for it. We will do this from a piece nichrome wire. To solve the problem, take 350 mm of material with a thickness of 0.2 mm and wind it onto the prepared tube. When you wind the wire, lay the turns very tightly together. Don't forget to leave straight ends. After winding, lubricate the spiral with a mixture of talcum powder and glue and let it dry until completely baked.
We are completing the project
The third stage involves additional insulation and installation of the heater in a tin casing.
This work must be done very carefully. The ends that come out of our heater should also be treated with insulating material. In addition, use the mixture to treat any cavities that may have arisen due to lack of care.
The manufacturing process of this tool involves protecting the heater leads with heat-resistant insulating material and pulling the cord through a hole in the soldering iron handle. Screw the ends of the power wire to the heater terminals, then carefully insulate everything.
All that remains is to pack the heating element into a tin casing, and then place it evenly in place.
Now you can use this product. If you did everything correctly, you will get an excellent soldering iron, assembled with your own hands. With its help you can solder many interesting circuits.
Miniature wire-wound resistor design
This tool is suitable for small work. It is very convenient to solder various microcircuits and SMD parts. The design of the product is simple; assembly will not be difficult.
We will need an MLT type resistor from 8 to 12 ohms. The dissipation power should be up to 0.75 W. Also select 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 PCB, a wire with heat-resistant insulation.
Before assembling this soldering iron with your own hands, remove 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. The tip will be mounted there.
At the very beginning, the hole diameter can be 1 mm. After processing it with a countersink, the tip should not come into contact with the cup. It should be located in the resistor housing. Make a special groove on the outside of the cup. It will hold a current conductor, which will also hold the heater.
Now we make the board. It will consist of three small parts.
On the wide side, connect a steel current conductor to it; in the middle part, the housing from the handle will be fixed. The second remaining resistor terminal is installed on the narrow part.
Before you start working with this tool, wrap the tip in a thin layer insulating material. So simply and easily you got a low-power 40 W 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 to technicians from service centers for repairing computers, laptops and mobile devices. For the home handyman This equipment is not readily available due to its cost. We hope this article will tell you how to make a soldering iron with your own hands quickly and easily.
A USB soldering iron, familiar to many, is a device for soldering parts, powered by a specialized computer connector.
In addition to the device itself, the delivery set of this device includes a connecting cord one and a half meters long, as well as a small metal stand and several coils of solder rolled into a spiral.
Externally, the USB soldering iron looks like a wireless product equipped with a special connecting cord. The mini soldering iron is also equipped with a special plastic plug that protects its working tip from accidental damage.
As for the one and a half meter connecting cord, one of its ends is made in the form of a classic USB connector, and the second ends with a regular 3.5 millimeter power “Jack”.
The manufacturer organizing the supply of portable USB soldering irons to domestic market, the following performance characteristics are guaranteed:
- small dimensions and compactness of the device, which greatly facilitates its handling during the soldering process;
high speed of heating the tip (this takes no more than 15 seconds); - fairly rapid cooling of the working tip (usually 25-30 seconds is enough);
- the power consumption of the device does not exceed 8 watts;
- operating power - from a USB connector with a voltage of 5 Volts;
- the presence of a timer that automatically turns off the mobile device after a programmed period of time.
The soldering iron is turned on when you touch its body with your hand (due to the built-in touch sensor).
Finalization
The main advantages of a USB soldering iron (almost instant heating and the presence of an automatic switching mode) in practice turn into disadvantages, the elimination of which requires its modification.
These disadvantages are expressed as follows:
- severe overheating of the tip in the absence of forced cooling;
- premature switching on of the soldering iron, associated with increased sensitivity of the sensor and also leading to overheating;
- a delay in turning off the device, in some samples reaching 45 seconds, as a result of which the same overheating and failure of the device are observed.
These deviations from the norm are found in most reviews of the operation of heating devices of this class and require changes to their electronic circuit.
Based on all of the above, independent modification of a soldering USB device should be reduced to the following.
Firstly, it is necessary to slightly reduce the sensitivity of the built-in sensor, which should respond clearly when touched by hand. To do this, it is enough to solder an additional capacitor with a capacity of about 2.2 nF between the touch contact and the ground power bus.
Secondly, the delay time for turning off the soldering iron after returning to the stand should be reduced, which will eliminate dangerous overheating. For this purpose, it is necessary to reduce the value of the timing resistor connected to the NE555 timer from 200 to 47 kOhm.
Upon completion of all these modifications, working with a USB soldering iron is greatly simplified, since after reducing the sensitivity, you can control the heating of the device directly during operation. These improvements also extend the life of the heating element.
Positive reviews
Among the user reviews about the operation of the USB soldering iron, its advantages are especially noted, such as its almost pocket format, which allows you to store it directly in your work clothes.
The advantages of this device also include a high heating rate of the tip and automatic disconnection from the power line. The soldering iron fits comfortably in your hand and allows you to melt solder in any spatial position.
Individual users are not limited to just technical advantages USB soldering iron, and also note the excellent design and ease of use of the soldering device.
Particular attention is drawn to the fact that the USB-powered device is quite mobile and can be used to repair the on-board power supply systems of modern cars equipped with the appropriate connectors.
Flaws
Some users attribute the disadvantages of a mini soldering iron to the insufficient power developed by the heating element.
Sometimes it is not enough to warm up the soldering zone and, especially, when working with large and thermally resistant metal products.
An analysis of user reviews showed that many radio amateurs prefer to use a USB soldering iron to work with small details and most often they connect it not to a computer, but to a separate adapter or unit.
And this is explained, first of all, by the fact that it is advisable to use the corresponding computer connector for its intended purpose, without loading it with a sufficiently powerful consumer.
This device is ideal for the initial training of young radio amateurs, since its circuit does not contain life-threatening high voltage.
In addition, after soldering, children often forget to unplug a regular electric soldering iron from the mains, which in this case is done automatically.
To summarize all that has been said, we note that in general, the soldering device with a USB connector fully complies with the characteristics stated in its technical description.
However, the greatest return from such a soldering iron can be achieved only after minor modifications to it. electrical diagram, the procedure for which was described earlier.
A soldering iron is an attribute of any radio amateur, from a professional to someone who has just started. Today you can find soldering irons or even soldering stations of any size on sale. But they all have one big drawback - they are quite rough and have a long distance from the end of the tip 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 at the diagrams of miniature soldering irons on the Internet, I discovered 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 beginning radio amateur based on several instructions. The features of our future soldering iron include: a short 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 (spare), ease of manufacture, which will not require any special knowledge.
Homemade miniature low voltage soldering iron– drawing
An ordinary brush was used as a handle, which was previously sanded and varnished.
To secure the wires in the handle well, I used this homemade unit: I made a thread in a hollow rivet and glued it into the handle. Here you can easily fix the cable using a locking screw.
Next I moved on to making mounts for the heat shield. They were also made from hollow rivets, but with a smaller diameter. An M1.6 thread was created in them and the handles were glued into the holes.
The heating element was taken from an ordinary inexpensive Chinese soldering iron; after some manipulations with the dimensions, it fit our device perfectly.
This element has a power of 7 watts and a length of 6.5 mm. Power supply is provided by an adjustable power supply - from 0...18 Volts. In this case, the heating temperature can reach 280 degrees
An ordinary spring was glued into the back of the pen, which can be borrowed from an ordinary ballpoint pen. This part is necessary to protect the power cable from breaking.
The grounding and power wires are threaded into the cambric. A grounding socket is pressed into the main hole of the plug, which is intended for the cable, and power cables brought out through an additional hole.
As you can see in the picture, the resulting homemade miniature low-voltage soldering iron is barely the same size as an ordinary fountain pen.
Once, while walking through the expanses of Aliexpress, I saw a USB soldering iron on sale. I was surprised. Can a normal soldering iron be powered from USB, where the supply voltage is only 5 Volts? But out of curiosity, I still ordered this copy.
Convenient small soldering iron. Fits perfectly in the hand.
You can look at this soldering iron for yourself this link.
Weighs only about 20 grams
The kit includes a 1.5 meter cord with the following connectors at the ends:
as well as a stand for the soldering iron itself
All assembled it looks like this:
Block USB power supply take a power supply so that it produces a current of at least 2 Amps
Soldering iron energy consumption
In order to find out the power consumption of USB consumers, I have this device
I connect the soldering iron to the block through this device
When you turn on the soldering iron, the red LED on it lights up
So, the voltage supplied to the soldering iron is 4.9 Volts
The current consumed by the soldering iron is 1.44 Amperes
Therefore, the power consumption of the soldering iron is: P = IU = 1.44 x 4.9 = 7 Watt with kopecks.
Checking the soldering iron in operation
This soldering iron heats up very quickly due to its small dimensions. The fireproof thin nickel tip will serve you faithfully for a long time. IN as a last resort You can easily buy it on Aliexpress
The solder melts once and twice!
And of course, the best feature: automatic shutdown. If you do not touch the soldering iron, it will automatically turn off after 25 seconds! As soon as we want to pick it up, the contactless sensor on it is triggered, and the soldering iron is ready for battle again. Well, honestly, I didn’t expect this from the Chinese.
Conclusion
Well, what else can you say about this soldering iron? It is unlikely that you will be able to solder large parts, but various small things will work just fine. Can it be powered from a USB computer or laptop? Mmm... Well, I plugged it into a laptop and it worked fine for me, but I strongly do not recommend doing this! Still, it is better NOT to use the USB ports of your computers to power the soldering iron. As you remember, they are intended for other purposes. If you buy a Power Bank in addition to it, you can solder even in an open field. This is much more convenient than using a bulky and smelly gas soldering iron.
Such a soldering iron will be an excellent purchase for young radio amateurs, since many of them forget to unplug the soldering iron from the outlet, and also in such a USB soldering iron there is no voltage of 220 Volts, which in itself is considered unsafe. So, parents, if you still want to buy for your child good soldering iron, take a closer look at this USB soldering iron. I've been using it periodically for a month now. He showed himself with the best side. Reviews on the Internet about it are also good. Further use will show what this soldering iron is capable of in terms of longevity ;-)
