LORCH P-Basic, Руководство по обслуживанию, Страница: 7 / 68

Inverter Principle
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3 Inverter Principle
A welding inverter is a electronically controlled welding power source. At conventional transformer based
machines, the mains voltage with 50/60 Hz is directly switched to the welding transformer. At a welding
inverter the mains voltage is rectified first and with electronic power switches (MOSFETs or IGBTs) chopped
into a frequency of 80 kHz. This allows a very small construction of the welding transformer, because it‘s
driven at this high frequency.
The basic structure of a welding inverter is always the same at Lorch power sources:
–
mains filter
– power-up circuit
– mains rectifier
–
primary inverter
–
transformer
–
secondary rectifier
mains
filter
3 phase mains
input
rectifier
primary
driver
transformer
secondary
rectifier
power
up
Fig. 3: Inverter principle