Page 44 - CITS - Welder - Trade Theory

WELDER - CITS

Lesson 8&9 : Arc welding power sources - AC welding

transformer

Objectives

At the end of this lesson you shall be able to
• state the necessity of an AC arc welding machine
• state the working principal and parts of AC arc welding machine.

Introduction: AC welding transformer –This is type of AC welding machine which converts AC supply into AC
welding supply.
It is a step down transformer.
Reduced the main supply voltage (220V or 440 volts)
To welding supply open circuit voltage (OCV). between 40 and 100volts
Increases the main supply low current to the required high output welding current in hundreds of amperes (300
-400 amps)

AC transformer construction
It consists of an iron core made out of a special alloy thin iron sheet stamping.
Two coils of wire are wound over the iron core without any inter connection between them.

One coil, called primary winding, consists of a thin conductor and has more turn which receives energy from the
mains.
The second coil, called secondary winding, consists of a thick conductor and less turns which supply energy for
welding.
A current regulator is attached to the secondary output supply to adjust the amperes forwarding
Parts list

1 Body, Holder connector, Earth connector, Holder cable, Earth cable, handle for current setting, Primary coil,
secondary coil,

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