XSD Series Medium Frequency Inverter DC Spot Convex Welding Machine Working Principle1. Power conversion and output: Power frequency alternating current (380V/50Hz) is first converted into DC power through the rectifier circuit, and then inverted to medium frequency AC (usually 1kHz-10kHz) through an inverter composed of IGBT and other power devices, and finally output by secondary rectification, stable DC welding current (no AC zero crossing interruption). 2. Welding energy concentration: DC current is applied to the contact point of the workpiece through the electrode, using the contact resistance of the workpiece and its own resistance to generate Joule heat, so that the contact area quickly melts to form a molten core. 3. Pressure and Time Collaborative Control: The pneumatic drive electrode exerts stable pressure on the workpiece (pre-press→ welding→ holding pressure→ pause), and cooperates with precise current and time parameter control to ensure that the molten core solidifies and forms a strong welding joint. Advantages More stable welding quality: DC current without zero interruption, continuous and uniform heat input, avoiding “cold welding” or “overburning” caused by current fluctuations in AC welding machine; At the same time, the current adjustment accuracy can reach 1%, which can accurately match the welding needs of different materials/thicknesses, and the solder joint strength is consistent.  Stronger material adaptability: For highly conductive/thermal conductivity materials (such as aluminum and copper), the high current of DC can break through the limitation of “skin effect” and provide sufficient heat.  Energy saving and high efficiency: The conversion efficiency of intermediate frequency inverter technology reaches 85%-95% (only 50%-60% for power frequency welding machine), and the energy consumption is reduced by more than 30% under the same welding effect; And the welding speed is fast, suitable for mass production.  Small welding deformation: The heat is concentrated in the solder joint area (the heat-affected zone is 30%-50% smaller than that of the power frequency welding machine), and the overall heating of the workpiece is uniform, especially suitable for welding thin plates or precision components, reducing the subsequent correction process.  Good grid adaptability: It is not sensitive to grid voltage fluctuations, the input current waveform is close to the sine wave, and the harmonic pollution is small, which can be integrated into automated production lines to reduce interference with other equipment. Industry Applications Automobile Manufacturing: Body welding: lap welding joints of high-strength steel (hot-formed steel) and aluminum alloy sheets, welding of thick plates and thin plates such as motor leads, battery housings, welding suspension connectors, drive shaft brackets, etc.  Electronic and electrical industry: spot welding of enameled wires and terminals, laminated convex welding of silicon steel sheets.  Precision parts of home appliances: washing machine inner cylinder (stainless steel), air conditioner evaporator (aluminum tube and fins), refrigerator condenser solder joint.  Aerospace field: welding of lightweight alloy components such as aluminum alloy and titanium alloy (aircraft skin, spacecraft mount)  Power battery and energy storage industry: welding of lithium battery electrode pieces (copper foil/aluminum foil) and electrode connectors (copper-aluminum composite strip), low spatter, and zero-false welding Medical devices and precision hardware: welding of small-sized components such as stainless steel surgical instruments (hemostats), precision shelves (cold-rolled steel plates), and sensor leads. Weldable materials Carbon steel and low-alloy steel, aluminum alloy and magnesium alloy, copper and copper alloy, coated steel plate