15Ap1:4 Charging Circuit - ESAB Aristo Mig 3001i Service Manual

15AP1:4 Charging circuit
When the mains power supply is turned on, smoothing capacitors 15C1 and
15C2 charge up via resistors R15 and R16.
When there are gate pulses present at pulse transformer TR2, transistor Q19
pulls the 'shutdown' signal to 0VA.
PWM circuit IC2 generates gate pulses to the thyristor in IGBT module IC8, the
thyristor short-circuits resistors R15 and R16.
Resistors R17 and R18 are potential dividers and discharge resistors for 15C1
and 15C2.
The PWM circuit generates a reference voltage +5.1 V, this is used by the
over/under voltage and temperature monitoring circuits.
S0740 800 196/E101019/P76
ca41_15_1 - 21 -