In the list of basic tools home craftsman not the last place is occupied by soldering irons. Depending on what they are intended for, their appearance and their designs can be very different from each other. To use, for example, the same tool for soldering a car radiator and working with microchips and transistors is impossible.
A soldering iron is needed for soldering various microcircuits and parts.
Buy a soldering iron with the desired characteristics is not always possible. But it is quite possible to make such an electric soldering iron with your own hands, especially since this work doesn’t represent any particular complexity - there would be time and desire.
Soldering iron with a resistor as a heating element
The easiest way to manufacture tools in which a sufficiently powerful resistor acts as a heating element. Let us examine a few examples of how to make a soldering iron of this design.Back to table of contents
Wire Resistor Soldering Iron
The device soldering iron "gun".
It is clear that in order to make such a soldering iron with your own hands, you need a suitable wire resistor. For a soldering iron with a voltage of 12 V, which can be powered not only from a suitable current source, but also from a car battery, a resistor with a nominal value of 20 ohms calculated for a power of 7 W will be suitable.
In fig. 1a and 1b show the appearance of the heater from two opposite sides. The individual elements on them are indicated by the following numbers:
- Bounding wire washer.
- A piece of soldering iron tip with a power of 25 watts.
- A piece of soldering iron tip with a power of 60 watts.
- Cog with a restrictive washer.
Figure 1. Heater padding.
A segment of the tip from a 60 W soldering iron (3) fits snugly into the hole of the resistor. A hole is drilled from one end and a thread is cut under the screw (4), and from the opposite side - under a segment of the tip of a 25-watt soldering iron (2). In addition, a groove for the restrictive wire washer (1) is made on its surface. It can be made of a ringlet, bitten off from a suitable spring.
The resulting heater must be supplemented with a pistol grip or the one shown in fig. 1. It can be connected to a car battery through a plug for a car cigarette lighter. A soldering iron with a voltage of 220 V can be made of a resistor with a resistance of 1700-2000 Ohms and a power of at least 10 watts. The handle can be taken from the burnt-out soldering iron.Back to table of contents
Miniature soldering iron of non-wire resistor
Using such a tool it is convenient to carry out fine work, for example, soldering chips. To make this soldering iron with your own hands, you will need the following materials:
- the resistor MLT nominal value of 8-12 Ohms with a power dissipation of 0.5 W;
- body from a pen;
- 1 mm thick piece of copper wire for the tip;
- a piece of steel wire with a diameter of 0.75 mm;
- a piece of double-sided PCB;
- wires in heat-resistant insulation.
Figure 2. The sting before insertion is necessary to wrap a thin layer of mica.
First of all, paint is removed from the resistor body. It can be removed with a knife or slightly holding the resistor in acetone. One of the conclusions is cut, at the place of the cut, a hole is drilled, and then a hole for the future sting is cracked (see Fig. 2a). The initial hole diameter is 1 mm, after rezsenkovki sting should not touch the cup, it should be kept in the ceramic case of the resistor. In the outer part of the cup, a groove is cut for fastening a steel current lead (see Fig. 2b). It also holds the heating element.
A small board is cut out of the PCB (see Fig. 2c). It consists of three parts:
- a steel current lead is soldered to the wide part;
- the middle part is used for fastening in the body of the pen;
- the second output of the resistor is soldered to the narrow part.
The soldering iron assembly is shown in Fig. 2g. The sting before insertion should be wrapped with a thin layer of mica. For power supply, it is desirable to use an adjustable current source. When using a resistor of 8 ohms, the operating voltage should be about 6 V.Back to table of contents
Low voltage do-it-yourself soldering iron
Figure 3. The device soldering iron.
Let us consider how to make an electric soldering iron with a heater of nichrome wire. In fig. 3 shows its schematic arrangement. In the figure, the individual structural elements are indicated by numbers.
In addition, you need a copper foil - the base for the heating element, talc and liquid glass (silicate glue) for the preparation of heat-resistant electrical insulating paste. If there is no copper foil, you can separate it from the foiled fiberglass, heating it with a preheated iron. To power the soldering iron you need a current source capable of delivering a current of 1 A at a voltage of 12 V.
Let's start with the manufacture of the heating element. Its base is a 30 mm long copper foil tube rolled around the soldering tip. It is carefully covered with a layer of insulating paste consisting of talc diluted in liquid glass to the state of thick dough. Then this layer at a temperature of 100-150oC dried to complete sintering of the paste.
The heating element is made of nichrome wire with a diameter of 0.2 mm and a length of 35 cm. It is neat, the coil to the coil is wound on the prepared base in one layer. The winding is covered on top with the same insulating paste and dried again. The ends of the nichrome wire should also be covered with paste to half the length. The remaining ends will later be connected to the power cord.
In the cross section of the heating element in Fig. The 3 numbers indicate the following items:
- copper sting - 8;
- base (copper foil tube) - 9;
- winding from nichrome wire - 10;
- 11 layers of electrical insulating paste.
The final stage is the assembly of the electric soldering iron. The electric cord is pulled through the inner hole of the handle and is connected to the terminals of the electric heater. The contact points are isolated, the heater is mounted in a protective cover made of tin, and the cover is connected to the handle.
To make a soldering iron, reliable and functional, with the necessary characteristics is not such a difficult task.