23/07/2026
AC & DC Welding Machines
The main difference between AC (Alternating Current) and DC (Direct Current) welding machines is the type of electrical current they use, which affects arc stability, pe*******on, spatter, and the kinds of jobs they’re best suited for.
DC Welding
Advantages:
* Smooth, stable arc.
* Easier for beginners.
* Better weld quality.
* Less spatter and easier slag removal.
* Works with most electrodes (e.g., E6010, E7018, E6013).
Disadvantages:
* More expensive.
* Can suffer from magnetic arc blow.
AC Welding
Advantages:
* Lower equipment cost.
* Eliminates magnetic arc blow.
* Good for welding magnetized steel.
* Suitable for some electrodes like E6011 and AC-specific E7018.
Disadvantages:
* Harder to strike and maintain the arc.
* More spatter.
* Produces a rougher bead compared to DC.
AC Welding Machine (Transformer Type)
Characteristics:
* Large and heavy transformer design
* Usually has a current adjustment k**b or lever
* Commonly used for basic SMAW (stick welding)
* Lower cost but consumes more power
Voltage (V)
* Voltage alternates between positive and negative.
* The arc briefly extinguishes every time the current crosses zero, making it less stable.
* Machines often use a relatively high open-circuit voltage (50–80 V) to make arc starting easier.
DC Welding Machine (Inverter Type)
Characteristics:
* Compact and lightweight
* Digital or analog amperage control
* Stable arc with less spatter
* Ideal for E6010, E6013, E7018, and most welding applications
Voltage (V)
* Voltage maintains the same polarity.
* Produces a smoother, more stable arc.
* Typical open-circuit voltage is 50–90 V, depending on the machine.
