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Welding power supply basics
Release time：2022-07-28
What is welding power?
An apparatus that supplies electrical energy required for welding and has electrical characteristics suitable for welding is called a welding power source.
Why are there special requirements for arc welding power supplies? What are the requirements?
In order to ensure stable welding of welding arc and adapt to various welding process requirements, arc welding power supply has the following special requirements:
1. The static characteristic (or external characteristic) of the arc welding power source is the relationship between the steady-state output current and the output voltage, and has a falling characteristic (constant current characteristic) and a flat characteristic (constant pressure characteristic).
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2. Dynamic characteristics of arc welding power supply When the load state changes instantaneously (such as: short circuit transition of droplets, particle transition, jet transition, etc.), arc welding power supply output current and output
The relationship between voltage and time is used to characterize the ability to respond to load transients (ie, dynamic response capability), referred to as "dynamic characteristics."
3. The no-load voltage is the voltage displayed by the power supply before the arc.
4. Adjusting the characteristics - changing the external characteristics of the power supply to meet the requirements of the welding specification.
Why does the arc voltage change when the arc length changes?
Determined by the external characteristics of the arc welding power source, the longer the arc, the higher the arc voltage; the shorter the arc, the lower the arc voltage.
What is arc stiffness?
The extent to which the arc is straight along the axial direction of the electrode under the effects of heat shrinkage and magnetic contraction.
Why is the welding arc blown?
During the welding process, the arc center is offset from the electrode axis due to the interference of the air flow, the action of the magnetic field or the eccentricity of the tungsten needle.
What is the load continuation rate of the welder?
Load duration refers to the ability of a welding power source to operate continuously at a certain current. The national standard stipulates that the manual welding rated load duration is 60%, and the automatic or semi-automatic is 60% and 100%.
What is the load continuation rate of the torch?
Refers to the ability of the torch to work continuously at a certain current.
What is the positive connection method?
The welding method is connected to the positive pole of the output end of the welding machine, and the wiring method of the negative electrode of the welding torch (welding tongs) connected to the output end is called "positive connection method", which is also called positive polarity.
What is the reverse connection method?
The welding piece is connected to the negative pole at the output end of the welding machine, and the welding method of the welding gun (welding tongs) connected to the positive terminal of the output end is called "reverse connection method", which is also called reverse polarity.
What is the starting current (initial current)?
In the "Yes" state of the arc, press the arc current of the torch switch; release the torch switch and switch to the welding current.
What is the arc current?
In the "existing" state of the arc, it is used to fill the crater at the end of the weld and reduce the crater defects (such as fire cracks, etc.).
What is the arc current?
In the "existing" state of the arc, it is used to fill the crater at the end of the weld and reduce the crater defects (such as fire cracks, etc.).
What is the rise time?
The transition time from the initial current to the welding current.
What is the fall time?
The transition time from the welding current to the arcing current.
What is pulse welding current?
Peak current during pulse welding.
What is the base welding current?
Minimum current during pulse welding
What is the lag time?
That is, after the welding arc is extinguished, the protective gas is delayed by 0.3 to 5 seconds and then the gas supply is stopped.
