Ap1:3 Secondary Circuit - ESAB Caddyt Arc 150i Service Manual

Transistor Q5 is the switching element in a switched voltage supply. The
secondary voltage, +24 V, is sensed by IC2 and controlled by IC1.
The isolation voltage of transformer T1 and optocoupler IC3 is 4 kV.
2AP1:3 Secondary circuit
The secondary circuit delivers the following voltages:
+24 V
The voltage is controlled by IC1 on the primary side. It has a tolerance of
±0.6 V.
+5 V
The voltage is controlled by VR3. It has a tolerance of ±0.25 V.
- -15 V
The voltage is controlled by VR2. It has a tolerance of ±0.75 V.
+13 VB
This voltage is unregulated. It has a tolerance of ±1.5 V.
Early warning power shut down
If the voltage goes low, output PS4 generates a warning signal to the
processor on circuit board 20AP1 (see page 24). Transistor Q6 switches off the
fan, 15EV1, at the same time.
S0740 800 161/E061205/P66
- - 15 - -
ct27d_2