ESAB Caddyt Arc 150i Service Manual page 25

When power to the machine is turned off, the display also shows " "
to confirm that the processor has stored the current data.
+5 V and +2. V, version 2 of 20AP1
5
+5 and 2. V power supply, circuit board version 2
5
IC6 monitors the 24 V voltage supply to the 5 V regulator on circuit board
2AP1. IC16 monitors the 5 and 2. V supplies. Regulator VR4 supplies the
5
processor with +2. V.
5
The voltage on terminal PS4 is normally about 24 V, when this drops below
20 V, pin 14 of IC6 goes low, providing the processor with a low power supply
voltage signal. The processor then stores current data and generates fault
code E4. When the 5 and 2. V voltages are passing below their treshold
5
values, the processor receives a reset signal from IC16.
Fault code E4 is not displayed at normal power off
+15 V and +20 V
Voltage regulator VR2 produces an output voltage of +20 ±1.0 V, which
supplies the pulse width modulator output stage. The voltage can be tested by
a service function:
Circuit board version 1, see service function no. 24 on page 39.
Circuit board version 2, see service function no. 17 on page 42.
Potential divider R70/R75 supplies 2.6 V to the processor. This provides a
signal that the power supply is available.
Voltage regulator VR2 produces an output voltage of +15 V, and this, together
with the --15 V supply, powers the analogue circuits.
S0740 800 161/E061205/P66
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