Working Principle; Olt -Ampere Characteristic - Matco Tools MG208 Operator's Manual

§2.2 Working Principle
The working principle of M-SERIES arc welding machine is shown as the following figure. single-
phase 110 or 220V work frequency AC is rectified into DC（154V）, then is converted to medium
frequency AC (about 37KHz) 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. Meanwhile, the welding current parameter can be
adjusted infinitely to meet with the requirements of welding application.
§2.3 Volt-Ampere Characteristic
The inverter has an excellent volt-ampere characteristic, whose graph is shown as the following
figure. The relation between the rated loading voltage U
U =14+0.05I (V)
2 2
（V）
U
o
§2.4Principles of welding
OVERVIEW
Volt-ampere characteristic
Working point
44
14
0
and welding current I
2
The relation between the rated loading
voltage and welding current
600
7
is as follows:
2
（A）
I
o