How does an electric soldering iron work and how to choose it?
Electric soldering iron is an essential tool for us when conducting circuit welding. A thorough understanding of the working principle of electric soldering iron not only helps us better use it, but also enables us to have a clear understanding of it and avoid any danger.
A constant temperature soldering iron
Thermostatic electric soldering iron achieves automatic temperature control through the attraction and separation of soft magnetic materials and magnetic steel. A constant temperature electric soldering iron is generally 45W, with intermittent power on and off. The actual power consumption is 25W, and a transformer 24V power supply is used for both AC and DC purposes.
Working principle: As shown in the figure, when the temperature of the welding head is below the constant temperature value, the magnetic temperature sensor connected to the welding head end attracts the permanent magnet, making the contacts on the magnetic steel connecting rod connected. The power supply is sent to the heating element, causing the temperature of the welding head to gradually increase. When the temperature is higher than the constant temperature, the heating element loses its magnetism, the power is cut off, and the heating is stopped. This cycle of automatically turning on or off the power supply, heating and cooling, and maintaining the electric soldering iron in a constant temperature state. If the model of the heating element is changed, different constant temperature values can be obtained.
Thermostatic electric soldering iron has the advantages of energy conservation, high efficiency, low consumption, and long service life, making it an ideal welding tool for the electronic product production and electronic repair industry.
How to choose an electric soldering iron?
(1) When welding integrated circuits, transistors, and their components that are prone to damage due to heat, consider using a 20W internally heated or 25W externally heated soldering iron.
(2) When welding thicker wires or coaxial cables, consider using a 50W internally heated or 45-75W externally heated electric soldering iron.
(3) When welding larger components, such as metal chassis grounding pads, an electric soldering iron of over 100W should be used.
(4) The shape of the soldering iron head should adapt to the surface requirements of the welded part and the assembly density of the product.
In brief, the power and type of electric soldering iron should be reasonably selected according to the welding object. The power of the electric soldering iron should also be higher when the weldment is larger. If the power is smaller, the welding temperature is too low, the solder melts slowly, the flux is not volatile, and the solder joints are not smooth and firm. This will inevitably lead to unqualified appearance quality and welding strength, or even the solder cannot be melted, and welding cannot be carried out. But the power of the electric soldering iron should not be too high. If it is too high, it will cause excessive heat to be transferred to the welded parts, causing overheating of the solder joints of the components, which may cause damage to the components, causing the copper foil of the printed circuit board to fall off, and the solder to flow too fast on the welding surface and cannot be controlled
