source:Qi Liang Reading volume:661 time:2019-04-12
Firstly, in the high frequency welding machine, a set of unique electronic circuits transforms the low frequency AC (50Hz) input from the power grid into high frequency AC (generally over 2000 Hz). When high frequency current is added to inductance coil (induction coil), it is converted into high frequency magnetic field by electromagnetic induction principle and acts on metal objects in magnetic field. Using eddy current effect, the induced current in metal objects is proportional to the intensity of magnetic field. This eddy current is affected by skin effect. The higher the frequency, the more concentrated it is on the surface of metal objects. When eddy current flows in a metal object, it generates heat based on the principle of current-heat effect with the help of inherent resistance. This heat is generated directly inside the object.