Service manual

Edition 101222
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s1Cad160
AP2:3H. Thermal protection on the primary side
As temperature sensors (sensor) are on the high voltage potential, the thermal
protection circuit (fig. ) is placed on the high voltage side, then the 0/1 signal is
transferred via the optocoupler IC2 with extended isolation, to the secondary
circuits.
Low Voltage Circuits
Low voltage circuits (secondary side) are placed on the left part of the PCB and
they are connected to the external circuits by means of the connector existed
connectors, except the CN1.
Low voltage circuits include:
S command system of the semiautomatic welder
S short arc control system
S wire feeder motor speed control circuit
S low--energy control of the electromagnetic valve
AP2:1L. Command system
Command system produces assumed program control on discrete inputs and
outputs. In particular it provides logic dependencies and generates the sequence
control of parts of the semiautomatic welder.