15Ap1:5 Gate Driver Stages And Switching Circuits; 15Ap1:6 Fan Control - ESAB Aristo Mig 3001i Service Manual

15AP1:5 Gate driver stages and switching circuits
WARNING!
Dangerous voltage - mains voltage. Never measure the gate signals when
the power source is connected to the mains supply.
The gate pulse frequency is 40 kHz. See page 50 for screen traces of
waveforms and measurement instructions.
Transformers TR2 and TR3 are gate driver transformers for galvanic isolation
of the drive circuits from controller board 20AP1.
If an IGBT module has failed, both the power board and the modules Q3 and
Q8 must be replaced. Failure of either module always subjects rectifier bridge
2BR1 to a high current surge, which substantially reduces its life. We therefore
recommend that the rectifier bridge should also be replaced if the modules
have failed. See page 46 for instructions on checking the IGBT modules.
The IGBT modules and circuit board 15AP1 must be mounted in accordance
with the instructions on page 54.
15AP1:6 Fan control
See 20AP1:2 on page 27.
ca41_15_1
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S0740 800 196/E101019/P76