What is the difference between internal heat and external heat of soldering iron?
(1) Internal heating soldering iron:
As the name suggests, "internal heat" refers to "heating from the inside". Therefore, the relative position between the heating element and the copper head should be "the heating element is inside the soldering copper head" or interpreted as "the soldering iron head is placed outside the heating element", allowing heat to be transferred from the inside to the soldering iron head. It has the advantages of fast heating, high heating efficiency, small size, light weight, low power consumption, and flexible use. Suitable for soldering small components. However, due to the high temperature of the soldering iron tip, it is prone to oxidation and blackening, and the soldering iron core is easily broken. Moreover, the power is low, with only a few specifications such as 20W, 35W, and 50W.
From the above explanation, it is clear what kind of soldering iron is an internal heating soldering iron. Here, we will further illustrate with the above diagram:
The shape of the soldering iron tip used for internal heating electric soldering iron is a hollow cylinder, and the heating element is covered by the soldering iron tip, so that its heat is not easily dissipated into the air. Therefore, the heat utilization efficiency is high, the preheating time is short, and the power generally does not need to be too large to meet the requirements. Generally, the internal heating power is below 50W, and common internal heating electric soldering irons are around 20W~30W.
Here are some common pictures of internal heating soldering irons to avoid confusion.
Internal heating electric soldering iron
(2) External heating soldering iron:
As the name suggests, "external heat" refers to "heating outside", named after the heating resistor located outside the soldering iron. It is suitable for welding both large and small components. Due to the fact that the heating resistor wire is located outside the soldering iron tip, most of the heat is dissipated to the external space, resulting in low heating efficiency and slow heating speed. Generally, preheating takes 6-7 minutes before welding. Its large volume makes it inconvenient to solder small components. But it has the advantages of longer use time of the soldering iron tip and higher power, with various specifications such as 25W, 30W, 50W, 75W, 100W, 150W, 300W, etc.
