- Principle of inverter welding machine
Inversion and rectification are two opposite concepts. Rectification is the process of converting alternating current to direct current, while inverter is the process of changing direct current to alternating current. The arc welding power source using inverter technology is called an inverter welding machine. The inverter process requires high-power electronic switching devices, and the inverter welding machine using insulated gate bipolar transistor IGBT as the switching device becomes an IGBT inverter welding machine.
- Working process of inverter welding machine
Rectify the three-phase or single-phase power frequency alternating current and obtain a smoother direct current after filtering. The inverter circuit composed of IGBTs converts the direct current into tens of KHZ alternating current, which is stepped down by the main transformer and then rectified and filtered Obtain a stable DC output welding current.
Due to the high inverter operating frequency, the core cross-sectional area and the number of turns of the main transformer are greatly reduced. Therefore, the inverter welding machine can save metal materials to a large extent, reduce the size and weight, greatly reduce the power loss, and more The important thing is that the inverter welding machine can adjust the output current within microseconds, so it can realize the ideal control process required by the welding process and obtain a satisfactory welding effect.
Although the circuit is closed, it is precisely because the circuit is closed that the entire closed circuit and the current are equal; but the resistance everywhere is different, especially where the resistance is the largest at the unfixed contact. This resistance is physically It is called contact resistance. According to the law of thermal effect of current (also called Joule's law), Q=I square Rt shows that if the current is equal, the greater the resistance, the higher the heat, and the contact of the electrode is also connected to the metal body during welding. If the contact resistance is the largest, the electric heat generated in this part is naturally the most. The welding rod is an alloy with a lower melting point, which is naturally easy to melt. The melted alloy electrode core adheres to the object to be welded and then cools. Glue the welding objects together.
Since the inverter welding machine is a typical switching power supply (the output characteristics have great characteristics), the output power is large, and the working environment changes greatly, so the quality of the components is required to be good, so as to ensure the stable work and long life.