Choice of soldering iron for household use
The soldering iron is an indispensable tool for us when welding circuits. Fully understanding the working principle of the soldering iron will not only help us use the soldering iron better, but also allow us to be aware of it and avoid danger. .
A constant temperature soldering iron
The constant temperature electric soldering iron realizes automatic temperature control through the attraction and separation of soft magnetic materials and magnetic steel. The constant temperature electric soldering iron is generally 45W. It is powered on and off intermittently. The actual power consumption is 25W. It is powered by a 24V transformer and can be used for both AC and DC. Let's directly analyze the circuit diagram of an electric soldering iron:
Working principle: When the temperature of the welding head is below the constant temperature value, the magnetic temperature sensor connected to the end of the welding head attracts the permanent magnet, so that the contacts on the magnetic steel connecting rod are connected, and power is sent to the heating element, causing the temperature of the welding head to gradually rise. . When the temperature is higher than the constant temperature, the heating element loses its magnetism, the power is cut off, and heating stops. In this way, the power is automatically turned on or off, the temperature rises and falls, and the soldering iron is kept at a constant temperature. If you change the model of the heating element, you can get different constant temperature values.
Magnetic switch
The constant temperature soldering iron has the advantages of energy saving, high efficiency, low consumption and long life. It is an ideal soldering tool in the electronic product production and electronic repair industry.
How to choose a soldering iron?
(1) When soldering integrated circuits, transistors and components that are easily damaged by heat, consider using a 20W internal heating or 25W external heating soldering iron.
(2) When welding thicker wires or coaxial cables, consider using a 50W internal-heating or 45-75W external-heating soldering iron.
(3) When welding larger components, such as the metal chassis grounding lug, a soldering iron of more than 100W should be used.
(4) The shape of the soldering iron tip must adapt to the surface requirements of the parts to be welded and the product assembly density.
To put it simply, the power and type of the soldering iron should be reasonably selected according to the object to be welded. If the parts to be welded are larger, the power of the soldering iron used should also be larger. If the power is smaller, the welding temperature will be too low and the solder will melt slowly. The flux is not easy to volatilize, and the solder joints are not smooth and firm, which will inevitably lead to substandard appearance quality and welding strength, or even the solder cannot melt and the welding cannot be performed. However, the power of the soldering iron should not be too high. If it is too high, too much heat will be transferred to the workpiece to be welded, causing the component solder joints to overheat, which may cause damage to the components, causing the copper foil of the printed circuit board to fall off, and the solder to be soldered. The flow on the welding surface is too fast and cannot be controlled.
