SMART PRO 5.0 Pág. 26
Working Principle
Working Principle
Working Principle
Working Principle
The working principle of SMART PRO 5.0 (PFC)welder is shown as the following figure. Single phase
208V
－
460V±10%work frequency (50/60 Hz) AC is rectified into DC, three phase 208V
－
460V±10%work
frequency (50/60 Hz) AC is rectified into DC, then by PFC circuit, DC(about 750V)is converted to medium
frequency AC (about 20KHz) by inverter device (IGBT module), after reducing voltage by medium transformer
(the main transformer) and rectified 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.
Meanwhile, the welding current parameter can be adjusted continuously and steplessly to meet with the
requirements of welding craft.
PFC
Inverter
Medium
frequency
transformer
Medium
frequency
rectify
Hall device
Current positive-
feedback control
Single-phase AC
DC
AC
DC
AC
DC
Rectify
208-460V 50/60Hz
208-460V 50/60Hz
Three-phase AC
Volt
Volt
Volt
Volt----Ampere Characteristic
Ampere Characteristic
Ampere Characteristic
Ampere Characteristic
SMART PRO 5.0 welders have excellent volt-ampere characteristic, seeing the following graph. In MMA
welding, the relation between the rated loading voltage U
2
and welding current I
2
is as follows:
When I
2
≤600A
，
U
2
＝
20
＋
0.04 I
2
（
V
） ；
When I
2
＞
600A
，
U
2
＝
44
（
V
）
.
64
44
20
0
600
I
2
（
A
）
U
2
（
V
）
Working
point
Volt-ampere characteristic
The relation of the rated loading
voltage&welding current
....
