Car soldering iron with his own hands

12 volt soldering iron

Among the large range of soldering equipment on the market of radio equipment, it is worth paying attention to mini electric soldering irons with 12 volt power. The small-sized tool appeals to many radio technicians for its miniaturization and decent performance.

12v soldering iron

Where a low voltage soldering iron is needed

When working with circuit boards filled with small radio components, special dexterity in handling a standard soldering tip is required. This creates a certain amount of inconvenience. This is where a low voltage soldering iron is irreplaceable.


Miniature 12 volt electric soldering iron is designed to work with small parts. It is convenient to solder the leads of various microcircuits, headphone wires, electronic components of watches and many other things.

Important! Home craftsmen use the micro soldering iron to create a variety of compact homemade electronic devices. For example, you can make yourself a USB charger for smartphones or other gadgets.

Main features

The main properties of the micro soldering iron include:

  • small size, ensuring the accessibility of the soldering iron in awkward places on printed circuit boards;
  • economical power consumption;
  • possibility to use different rechargeable batteries as a power source;
  • universality of power supply from both AC and DC;
  • simple design of NP allows it to be repaired.

Power limitations

It is necessary to pay attention to what power the mini soldering iron has. The safety of the work depends on it. For example, a 40W soldering iron with a voltage of 36 volts will require a current of more than 1A. A 12 volt 30W soldering iron will already require a current of more than 2A. Consequently, when selecting current carrying conductors, you must consider their cross-section corresponding to these characteristics.

Connecting a 12 V soldering iron

It is very important that the connection of the power cord to the power source was the safest. To do this, use a variety of connectors, entering tightly into the sockets of power units.

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Depending on the design of the NP, the required current characteristics of the power supply, and the types of power sources used, plugs, clamps, male plugs, or car cigarette lighter plugs are used.

Because mini-soldering irons do not have automatic heat control, they must be turned off periodically. Otherwise, the device will fail. To turn the soldering iron off quickly, the power plugs should be convenient in this regard.

Choosing a soldering iron

To make the right choice of soldering iron, you need to be clear about what kind of work it will be used for. Up to 40 watts of power is enough for a 12 volt NP to solder the connections of radio components.

When buying a soldering iron, you should check that the handle, body, and tip are tight and securely fastened. If the seller has no possibility to check the lead-tin solder melting or the temperature of the tip heating, it is better to refuse from dubious purchase.

Pay attention! Low-power tool is not suitable for soldering wire connections in the car. Large cross-section of the car electrical equipment cables will actively “take away” heat from the sting. In addition, it will be impossible to use the NP in cold weather.

Soldering iron with your own hands

There are many ways to make homemade low-voltage soldering irons. It is quite possible to make a 12 volt device with your own hands almost without much financial cost. Before you start making a soldering tool, you need to prepare the appropriate materials and tools.

The diagram of a 12v mini soldering iron


  • copper wire 40 x 1.5 mm;
  • A tube of thin tin or the body of a metal 4-color ballpoint pen;
  • nichrome wire;
  • wooden pen with a hole equal to the outer diameter of the tube;
  • PCB backing or copper foil;
  • electrical cord;
  • office silicate glue;
  • talcum powder or baby powder.


  • pliers;
  • tissues or rags;
  • tweezers;
  • file;
  • wire cutter;
  • spatula;
  • 220/12V step-down transformer;
  • household heater with an electric spiral or kitchen gas stove.
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Soldering iron assembly procedure

  1. The end of a piece of copper wire is ground with an emery on both sides in the form of a cone with an angle of 400.
  2. The cheeks of the tip are tinned.

NP tip

  1. Silica glue is mixed with talcum powder until you get a viscous sticky electrical insulating mass.
  2. The sting is wrapped with copper foil so that the tip of the wire remains 10 mm long.
  3. The resulting copper tube is coated with the adhesive mass.
  4. Then the electric insulating coating is subjected to heat treatment over a heater or a gas burner flame. You can do it with a heat gun.
  5. After the ceramicization of the insulation, the rod is wrapped with nichrome wire in tight coils in one layer.
  6. The viscous coating process is repeated.
  7. One end of the conductor is wrapped to the opposite end of the tube. It is also covered with adhesive and heated until it hardens.
  8. The cylinder is inserted into the casing so that it is held tightly in the body of the soldering iron.
  9. In turn, the casing is fixed in a wooden handle, passing through it the leads of the nichrome spiral.
  10. The power cord on one side is connected to the nichrome wire, on the other side – it is attached to the terminals of a step-down transformer or other 12 V current source.
  11. The transformer plug is inserted into the socket. It remains to wait for the heat of the tip to the melting point of the solder.

Heating element

Additional information. To soldering iron 12 volt worked from the cigarette lighter in the car, to the mains cord attached plug from an auto lighter.

Remodeling an old soldering iron

The old soldering iron 220 volt can be converted to 12 volt NP. To do this, proceed as follows:

  1. On the body unscrew the two screws and remove the sting.
  2. Remove the handle and separate the twisted wires of the power cord and heater.
  3. Lift the sleeve with a knife and remove the heating element from the housing.
  4. Remove the thermal fabric, mica sheaths, wind up two layers of nichrome thread. Subsequently, only the heating wire of the upper layer will be needed.
  5. At the front end of the tube (from the side of the stinger) fix a ring of copper wire, one end of which is twisted with a nichrome thread.
  6. A heating spiral is wound on the tube, the end of which is twisted with another piece of copper wire.
  7. The spiral is covered with a mica sheath.
  8. Bend the front copper wire to the tube and cover the rod with the second layer of mica.
  9. The leads of the copper wires are connected to the power cord.
  10. The heating element is wrapped with a thermal cloth and inserted into the casing of the soldering iron.
  11. Insert the stinger and fix it with screws.
  12. On the other side you put on the handle.
  13. The plug of the cord can be removed. In its place connect the connector that corresponds to the sockets of the power supply.
  14. The 12 volt soldering iron is ready to use.
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Making a soldering iron from a resistor

A simple mini device for soldering small parts is made from a simple resistor. To make it, you will need the following:

  • a domestic resistor (25 Ohm / 2 W);
  • small wooden bar;
  • Two pieces of copper wire in PVC sheathing;
  • AC adapter or a 12 volt screwdriver battery.


  1. One of the resistance leads will serve as the stinger. It is stripped and left 1 cm long.
  2. The other end of the resistor should be no shorter than 1.5 cm.
  3. The front cap of the radio component is wrapped with a bare ring of one of the pieces of copper wire.
  4. After 50 mm, make a loop on the wire and fix it with a screw on a wooden rail.
  5. The stripped end of the second segment is soldered to the long terminal of the resistor.
  6. The free ends of the wires are stripped and connected to a 12 volt power supply.
  7. The tip of the mini-soldering iron heats up to the melting point of the solder after a few minutes.
  8. A wooden rail is used as the handle of the soldering iron.

Mini soldering iron from a resistor

What you need to know about the 12 volt soldering iron

The 12v soldering iron has a small sting, which is convenient for soldering the thinnest pins of microcircuits. The NP housing does not obscure the full view of the radio components on the circuit board or schematics of various gadgets. The tip of the mini-soldering iron will never overheat when in contact with a heat-sensitive component.

Various batteries are used as power sources for the NP: from a car battery, screwdriver battery, block of 18650 batteries to an ordinary 220/12V adapter.

A low-voltage soldering iron is so easy to make that it is not difficult for a home radio technician to make one himself. At the same time, you can buy a reliable tool at the best price at the radio market.

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A simple soldering iron for small parts from a car cigarette lighter

For a long time I wanted to buy a soldering iron for unsoldering small parts, such as smd, microchips, etc., but the prices of such soldering irons were usually good, so I decided to make it myself from an ordinary car cigarette lighter.

making by ourselves

For a long time I wanted to buy a soldering iron for unsoldering small parts, such as smd, microchips, etc., but the prices of such soldering irons were usually good, so I decided to make it myself from an ordinary car cigarette lighter.

So, as I said above we will need a car cigarette lighter, we need to take it and disassemble it piece by piece.

Simple soldering iron with your own hands

Of all these parts, we only need the heating element from the cigarette lighter itself, we don’t need the rest. Next, we need a tube suitable for the size of the cigarette lighter, I took such a tube from a children’s bicycle to it was attached to the seat.

from a car cigarette lighter

Insert the cigarette lighter into it.

into a tube with your own hands

Then you need a simple, paper clip. It should be straightened and wrapped around the top of the cigarette lighter, as shown in the photo.

At the branch of this wire put dielectric tube or you can wear a simple heat shrink instead of the tube,

making by ourselves

and at the very end screwed electrical terminal to connect the wires.

A simple soldering iron for small parts from automobile cigarette lighter

Then, on the metal, the main tube put a piece of polypropylene pipe and fasten them to each other with simple clamps (ties).

A simple soldering iron for small parts from automobile cigarette lighter

It is necessary to drill a hole through the two tubes, on the terminal side, in order to pull the wires through it.

A simple soldering iron for small parts from automobile cigarette lighter

One wire should be connected to the terminal, and the second connect to the back of the heating element or simply to the iron tube in which the cigarette lighter is inserted.

A simple soldering iron for small parts from automobile cigarette lighter

A simple soldering iron for small parts from automobile cigarette lighter

Then it remains only to make a plug of the tube and wrap with duct tape, just in case.

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A simple soldering iron for small parts from automobile cigarette lighter

The soldering iron itself is ready, now it remains to connect it to a power source. I took the 12 volt power supply that was intended to power the LED strip and plugged it in.

A simple soldering iron for small parts from automobile cigarette lighter

Now, unsoldering the small parts from the boards as well as re-soldering them was a pleasure. The soldering iron is great but it heats up and cools down quick.

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