STEALTH DIGI-MIG 200
2.3 Working Principle
The working principle of the Digi-Mig 200 welding machines is shown as follows:
Single-phase 220V work frequency AC is rectified into DC 350V, it is then converted to
medium frequency AC (about 40KHz) by the inverter device (IGBT). The reducing of
voltage using the medium transformer (the main transformer) whilst rectifying using
the medium frequency rectifier (fast recovery diodes) is outputted by inductance
filtering.
The circuit adopts current feedback control technology to ensure current output is
stable when MMA or TIG welding. It also adopts voltage feedback control technology to
ensure voltage output is stable when MIG welding. The welding current parameter can
be adjusted continuously and infinitely to meet with the requirements of all welding
processes..
2.4 Volt-Ampere Characteristic
The Digi-Mig 200 welding machine has an excellent volt-ampere characteristic, shown
in the graph below. The relation between the conventional rated loading voltage U
2
and
the conventional welding current I
2
is as follows:
U
2
=14+0.05I
2
(V).
9
OVERVIEW
- 8 -
§2.2 Working Principle
The working principle of MIG SERIES arc welding machine is shown as the following figure.
Single-phase 220V work frequency AC is rectified into DC
(
350V
)
, then is converted to medium
frequency AC (about 40KHz) by inverter device (IGBT), after reducing voltage by medium
transformer (the main transformer) and rectifying by medium frequency rectifier (fast recovery
diodes), and is outputted by inductance filtering. The circuit adopts current feedback control
technology to insure current output stably when MMA or TIG. And adopts voltage feedback
control technology to insure voltage output stably when MIG. Meanwhile, the welding current
parameter can be adjusted continuously and infinitely to meet with the requirements of welding
craft.
Rectifier
Inverter
Transformer
Rectifier
Hall
Current
Feedback
control
Single-phase AC
DC
AC
DC
220V 50Hz
AC
DC
Welding current
regulate
(Wire feed speed)
Wire feeder
motor
PWM signal
CPU control
Voltage
Feedback
control
§2.3 Volt-Ampere Characteristic
MIG SERIES welding machine has an excellent volt-ampere characteristic, whose graph is shown as the
following figure. The relation between the rated loading voltage U
2
and welding current I
2
is as follows:
U
2
=14+0.05I
2
(V)
Current sensor
OVERVIEW
- 9 -
44
14
0
600
I
o
(
A
)
U
o
(
V
)
Working point
Volt-ampere characteristic
The relation between the rated loading
voltage and welding current
§2.4Principles of welding