1. Welding quality

The adjustment cycle of the power frequency AC welding machine is relatively long, and for a 50Hz power grid, the welding time adjustment resolution is 20ms. The time adjustment resolution of the inverter DC intermediate frequency spot welding machine can reach 0.25ms (4kHz inverter frequency), with high control accuracy. The response speed of the feedback control of the inverter welding machine is significantly accelerated, and the output stability is good.

Due to the influence of zero crossing current, the thermal efficiency of power frequency AC welding machines is low. Thyristors are used to regulate the current. When the current percentage is small, the zero crossing time is long and the impact is greater; The output current of the inverter DC intermediate frequency spot welding machine is pulsating DC, and under the action of the circuit inductance, it is continuous DC output, with high thermal efficiency and stable welding heat input.

2. Welding speed

The power frequency AC welding machine has a relatively long heating time due to the influence of zero crossing current. The inverter resistor intermediate frequency spot welding machine has DC output, centralized heating, and shortened welding time.

3. Energy saving effect

The AC medium frequency spot welding machine operates at 50Hz, with high transformer losses, low power factor of the welding machine, and high circuit losses. The inverter welding machine transformer operates at a high frequency (1-4kHz) with minimal loss, and the DC output improves the power factor, resulting in significant energy-saving effects.

4. Equipment volume and weight

The transformer iron core of the power frequency AC welding machine is relatively large, and the equipment is bulky under the same power conditions. The transformer of the inverter DC resistance intermediate frequency spot welding machine is greatly reduced, and the equipment is relatively lightweight.