What are the characteristics of constant voltage operation mode of medium frequency resistance welding machine?
If the frequency sampling rate is high (usually minimum adjustment cycle 0.25ms~1ms), it is easy to control the welding process accurately and flexibly.The control modes of medium frequency direct current resistance welding machine include constant current control mode, constant voltage control mode and constant power mode, and some products have fixed pulse width control mode.Constant voltage mode features: constant voltage, less current in the second half. The reason is that when the workpiece is heated, the resistance increases, so that the current decreases. The aim of the model is to keep the joint temperature stable rather than increasing.
Advantages of intermediate frequency resistance welding machine:The power factor is extremely high (above 0.95), and the required power supply is saved by half compared with the AC resistance welder, and the three-phase balance of the power network is not influenced.Because of the direct current bunching effect and no zero crossing effect, the welding efficiency is improved and the required current is smaller. Therefore, the required cooling water is less, and the spatter is reduced, so that the electrode grinding cycle is lengthened correspondingly.If a transformer power frequency transformer size and weight can be reduced to one - to 1/3.The secondary loop is not affected by the ferromagnetism of the workpiece.There is no alternating electromagnetic force in the DC operation, so the electrode pressure is less.
The inverter type resistance welding machine outputs DC welding current with little ripple, and it will not affect the stability of electrode pressure, so it can be finished with smaller welding pressure. (this is the mid frequency inverter welding machine running cost of low characteristics of six)
