Introduction to the principles of soldering iron
Virtual soldering refers to the situation where only a small amount of solder is attached to the solder joint, resulting in poor contact and intermittent continuity. Fake soldering refers to the situation where the surface appears to be soldered, but in reality it is not soldered. Sometimes, by pulling it out with your hand, the lead can be pulled out from the solder joint. These two situations will bring great difficulties to the debugging and maintenance of electronic production. Only through extensive and careful welding practice can these two situations be avoided. When soldering circuit boards, it is important to control the timing. If it is too long, the circuit board will be burnt or cause the copper foil to peel off. When disassembling components from the circuit board, the soldering iron tip can be attached to the solder joint, and after the tin on the solder joint melts, the component can be pulled out. The temperature of a soldering iron is related to the volume, shape, length, etc. of the soldering iron tip. When the volume of the soldering iron tip is relatively large, the holding time is longer. In addition, to meet the requirements of different welding objects, the shape of the soldering iron tip varies, commonly including conical, chisel shaped, circular bevel shaped, and so on.
Measure whether there is an open or short circuit at both ends of the plug with a multimeter in the ohm range, and then measure the resistance between the plug and the housing in the Rx1000 or Rx10000 range. If the pointer does not move or the resistance is greater than 2-3M Ω, it can be used safely without leakage. The core of an internal heating electric soldering iron is made by winding a relatively thin nickel chromium resistance wire around a ceramic tube, with a resistance of about 2.5k Ω (20W), and the temperature of the soldering iron can generally reach around 350OC. Due to its fast heating, light weight, low power consumption, small size, and high thermal efficiency, the internal heating electric soldering iron has been widely used. After connecting the soldering iron to the power supply, if it is not hot or too hot, measure whether the power supply voltage is lower than AC210V (the normal voltage should be AC220V). If the voltage is too low, it may cause insufficient heat and difficulty in soldering. Oxidation of the soldering iron head or oxidation of the fastening part between the tip of the soldering iron and the inner wall of the outer tube. The reason for the electrification of the neutral wire is that in a three-phase four wire power supply system, the neutral wire is grounded and has the same potential as the ground. If neon bubbles emit light when tested with an electric tester, it indicates that the neutral wire is charged (there is a potential difference between the neutral wire and the ground). An open circuit in the neutral wire, an increase in the grounding resistance of the neutral wire, an open circuit in the grounding lead, and a grounded phase wire can all cause the neutral wire to become charged.
