15Ap2 Gate Driver Board; 15Ap2:1 Gate Driver Stages - ESAB Arc 4000i Service Manual

15AP2 Gate driver board

The gate driver board carries circuitry for gate driving and overvoltage and undervoltage
protection.
15AP2:1 Gate driver stages
WARNING!
Dangerous voltage - mains voltage. Never measure the gate signals
when the power source is connected to the mains supply.
The pulse frequency is 27 kHz, with a maximum pulse width of 39.0 -- 40.8 %
of the cycle width. See page 60 for screen traces of waveforms and
measurement instructions.
Transformers TR1 and TR2 are gate driver transformers for galvanic isolation
of the drive circuits from controller board 20AP1. Fuses S1 and S2 protect the
gate driver circuit if the IGBT transistors fail.
Transistor module 15Q1 has a diode connected in series with its emitter: this
transistor has the identification 'GAR' on its case. Transistor 15Q2 has a diode
in series with its collector, and is identified by 'GAL' on its case.
ct32_15
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S0740 800 191/E080229/P78