Page 47 - CITS - Welder - Trade Theory

WELDER - CITS

AC to DC Generator

Working principle of DC Generator
The armature is made to rotated with the help of a prime mover between the main poles, where a strong magnetic
field exists.
The armature cuts the magnetic lines of force, generating EMF in the conductors. The commutator, being
connected to the armature conductors, changes the generated alternative current into DC.
The generated DC is then taken to the generator terminal through the carbon brushes.
Note - Where the main supply electricity is available. Used as a prime AC motor.
Where main supply is not available, petrol or diesel engine may be used as a prime mover.
Diesel welding generator

Rectifier and inverter welding machine

Objectives: At the end of this lesson you shall be able to
• explain DC welding rectifier and inverter set
• explain the working principle of rectifier and inverter set.

Introduction to rectifier welding machine
A welding rectifier set is used to convert AC welding into DC welding supply. It consists of a step down transformer.
Welding current rectifier cell convert to AC to DC current.
The rectifier cell consists of a supporting plat made of steel or aluminum. Rectifier plate with a thin layer of nickel
or Bismith, spreyed with selenium or silicon.
It is finally covered with an alloyed film of cadmium, Bismith and Tin.

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CITS : C G & M - Welder - Lesson 8&9