20Ap1:5 Overvoltage And Undervoltage Protection; 20Ap1:6 Relay Driver Stages; 20Ap1:7 Gate Pulses; 20Ap1:8 Current Sensor - ESAB Aristo Mig 3001i Service Manual

20AP1:5 Overvoltage and undervoltage protection
See 15AP1:3 on Page 20.
20AP1:6 Relay driver stages
The relay driver stages are only used in the Tig 3001i and Mig 3001i with water
cooling unit.
For more information see: "10AP1 Tig board" on page 16 and "20AP2 Relay
board" on page 37.
20AP1:7 Gate pulses
See: "15AP1:5 Gate driver stages and switching circuits" on page 22.
20AP1:8 Current sensor
The current signal supplied to contact S3 on circuit board 20AP1 is 150 mA at
300 A, and is proportional to the current. Measuring the voltage between
contacts S3 and S4 on circuit board 20AP1 must show 0.195 V at 100 A
welding current. (U = R x I
If circuit boards 20AP1 or 15AP3 are replaced, the power source must be
recalibrated. See page 57 for calibration instructions.
Offset potentiometer R201 is not mounted on circuit board 20AP1. The offset
adjustment is carried out by fixed resistors.
On no load, there must be a voltage of 0 V $2 mV at input S3 of circuit board
20AP1. If the current sensor gives an incorrect value on no load, it must be
replaced.
Note! The sensor must be connected to 20AP1 when making the
measurement.
ca41_20_1
å
3. x 0. = 0.
91 05 195
- 31 -
)
S0740 800 196/E101019/P76