How to repair a soldering iron

An electric soldering iron is a hand-held equipment that allows using soft solders to connect parts to each other, heating the solder to a liquid consistency, filling them with voids between the connected elements. Before buying a tool, you should be familiar with the technical characteristics of the device, the rules of operation and how to repair the soldering iron.

Soldering iron

A soldering iron is a tool needed to carry out minor repairs of electronic devices.

terms of Use

There are models on the market that are suitable for operation from a network with a voltage of 12 to 220 V. In the process of choosing a tool, the need to ensure the safety of the craftsmen working with it and the voltage in the power grid at the work site are taken into account.

In rooms with a high level of humidity and grounded devices it is permissible to use a soldering iron with a voltage of up to 36 V and a mandatory earthing of the soldering iron body. Repair the tool is not needed if you comply with these requirements.

Electric soldering device

The device is an electric soldering iron.

When self-fabricating a soldering iron, a thin wire is used to wind the helix. Power and tool voltages must match. The power of such units reaches from 12 to 100 W and above, because it is possible to provide solder to a uniform spreading over the surface of the elements being joined, if they are heated more than its melting point. Heat from the tip is transferred to the parts upon contact, because of this the temperature of the sting decreases.

Insufficient power of the heating coil or a small diameter of the rod can prevent the tip from heating to the required temperature, which prevents soldering. Powerful soldering irons can connect small parts, but due to the size of the device, access to soldered elements is limited. Experts recommend winding copper wire with a diameter of 1 mm on the sting. High power of such devices allows you to quickly warm up the elements, and most small radio components, transistors, diodes, microcircuits do not withstand temperatures exceeding 70 ° C. The soldering time is reduced to 3 seconds. Before you repair the device in question, you need to find out its design features.

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Constituent elements

Scheme miniature soldering iron

Scheme miniature soldering iron.

The device under consideration is made of a copper rod, which is heated to the melting point of the solder using a nichrome spiral. When soldering parts it is necessary to ensure that heat is quickly transferred from the heating element to the sting.

The sting is the working part of the instrument, the rod with a wedge-shaped tip. It is inserted into a tube of steel, wrapped with fiberglass cloth or mica, on which a wire is wound, performing the function of a heating element. Nichrome wire is wrapped with asbestos, which helps reduce heat loss. To the conductors of an electrical cord with a plug, connect the ends of the nichrome spiral, which fold and fold to provide greater reliability and lower the heating temperature at the junction points with the copper wire. The connection is further compressed with a metal plate.

A nickel-chrome alloy helix and a copper sting are in a metal case, which can be made from a solid piece of metal or welded from 2 parts. On the metal tube, the housing is fixed using the overhead rings. Electric current after inserting the device plug into the socket enters the coil from nichrome, which, after heating, transfers heat to the sting.

Soldering iron soldering device for small parts

Adaptation to the soldering iron for soldering small parts.

Experts recommend for equipment rations of low-power diodes use equipment with a capacity of not more than 12 watts. Thick wires, large parts and small powerful parts need to be soldered using devices 40 and 60 watts. Large parts are soldered with units of 100 or more watts.

Quality of work cannot be guaranteed by selecting the right power tool. Improper operation of the unit leads to breakage and the need to repair the soldering iron.

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Step-by-step instruction

Independent manufacture or repair of heating devices is carried out taking into account the calculation of the resistance of the heating element or winding. Knowledge of the voltage and resistance of the electrical device allows you to calculate its power, which it consumes. The resistance in the winding of a 60-watt soldering iron powered by a 36-volt supply should reach 22 ohms. Proper selection of power and voltage helps to avoid breakage and the need to repair the device in question.

Schemes of temperature regulators & quot; stings & quot; soldering iron

Schemes of temperature control "soldering" soldering iron.

Then you want to choose the diameter of the wire from nichrome, comparable to the size of the winding. The winding of the helix with a resistance of 806 Ohm is performed using a 5, 75 m wire with a diameter of 0.1 mm (the resistance value is divided by 140) or 25.4 m wire - in 0.2 mm. The coils must be laid close together. The surface of the wire from nichrome will oxidize when incandescent, creating an insulating surface. The coiled layer that does not fit in the first row is covered with mica. Reel the second row. High-quality assembly allows a long time to operate the tool without breakdowns and repairs.

Heat and electrical insulation in the winding provides a coating of fiberglass, mica or asbestos. The advantage of asbestos over other compounds is that it can be soaked with water, creating the desired shape, and after drying, the material has a sufficiently high strength.

The main cause of the malfunction of the soldering iron is the breakage of the heating element.

Simple repair helps to restore its working capacity. To repair a soldering iron, you will need the following tools:

  • pliers;
  • sharp knife;
  • ceramic resistance "PEV-10";
  • asbestos thread.

Repair of an electric soldering iron is carried out in several stages. Pre-prepared ceramic resistor 1-1.5 ohms. In its central part there is a hole that allows you to skip the soldering iron rod without additional fitting.

Then the faulty heating element is removed. The prepared ceramic resistor is placed in the resulting socket. The next step is to connect the power wires to the resistor. For this it is recommended to use the channels in the handle of the device. Wires need to be laid so that they do not come into contact with the body, and the conclusions - to isolate the asbestos thread. Upon completion of the repair work, it will be necessary to assemble the component parts of the soldering iron in reverse order. To repair the soldering iron yourself, you will need its scheme.

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