Power Source

AC/DC TIG  Digital Welding Inverters

Features :

Constant Current Output Provided

The output of SigmaWeld Welding inverters are constant even if there is a power fluctuation in the mains of upto +/- 15%. The powersource works equally well with Generator Sets with balanced load.

Energy Saving , VRD Inbuilt

When the operator is not welding for more than 2 minutes, the power source automatically switches to low open circuit voltage output below 24V for safety of operator. This also leads to saving of no load losses.

Excellent Welding Performance

The parameters settable re Peak Current, Base Current, Peak Time, Base Time,Upslope Time, DownSlope Time, Gas preflow, Gas Post flow,Torch Mode (2 Track,4 Track), Frequency(AC Welding)

If the operator presses the torch switch but does not start welding,the Gas Solenoid is switched off within 10 sec. ensuring no wastage of Shielding Gas

In case the tunsten touches the job , the welding current and voltage are stopped immediately,helps avoid Tungsten Inclusion defects

The AC Model helps weld materials like Aluminium with great ease

Protections and Safety

SigmaWeld welding inverters are designed for Safety of both operator and machines. It has inbuilt protections for Overvoltage, Undervoltage, Output Short, Thermal Overload and IGBT Peak Current locking. This ensures longer life of equipment and our inbuilt Voltage Reduction Circuit which ensures OCV as low as 24 Volts or below when not welding keeps operators safe.

Water Cooling Unit Interlocking

SigmaWeld WCS (Water Cooling System) can be easily mounted below the SigmaWeld Welding inverters making in one completely integrated unit. The SigmaWeld WCS contains Stainless Steel Tank, Radiator and Forced Air Cooling. Interlocking of Water Cooling Unit with the program ensures that the WCS is operational only in the GTAW mode. This is to safe guard the Welding Torch and operator.

Welding Automation and Accessories

SigmaWeld GTAW machines can be controlled with the help of our standard push button based remotes, Potentiometer based remotes or Foot Controlled Remote for adjusting Welding Current during welding.

SigmaWeld GTAW machines can be interfaced with Robots, Welding SPM’s and other systems with ease.

SigmaWeld Automation Systems such as Weaving Units, AVC (Automatic Voltage Controllers), Special Purpose Machines, Cold Wire Feeders etc are specially designed to enhance productivity and quality of welding.


Specification SW 300 ACDC
Rated Input Voltage 3φ, 415V ± 15%, 50HZ
Power (KVA) @ 100% 12 KVA
Duty Cycle @ 400C 300Amps @ 80%
Open Circuit Voltage 60V
Output Range 5 - 300Amps
(D x W x H) mm 490 x 360 x 500
Weight 55 Kgs

Protection, Safety Features

1) Thermal Shutdown Inbuilt
(Over temperature Indication)
2) Under Voltage Inbuilt(Phase Failure Indication)
3) Over Voltage Inbuilt(Phase Failure Indication/MOV)
4) IGBT Peak Current In Built
5) Cooling Type Forced Air Cooled
6) Water Cooling Interlocking Water Flow Switch(optional)
7) Output Short Inbuilt (Output Short Indication)


1) Gas Pre Flow Time Settable 0.1 S 30.0 S
2) Gas Post Flow Time Settable 0.1 S 30.0 S
3) Peak Current Time Settable 0.1 S 10.0 S
4) Base Current Time Settable 0.1 S 10.0 S
5) Frequency Settable 10 Hz 100 Hz
6) Peak Current Settable 5 A 300 A
7) Base Current Settable 5 A 300 A

Optional Accessories

Operating Panel

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