ARC WELDING

ARC WELDING 

   The arc welding process is a fusion welding process in which an electric arc is st up between the material electrode and the work piece. electric arc welding is also defined as a welding is also defined as a welding process where in fusion is produced by heating with an arc , with or wothout the application of pressure and with or without the use of filler metal

i) AC Welding machine :-

          a step down transformer is used to obtain the welding energy for AC welding machine
 heat process primary and secondary crcuit. the primary side of which it connected to the main line supply and the secondary side connected to electrode and work table, the incoming supply from the main line to be 220 or 440 volt and outgoing supply may be of the order of 45 to 100 volt. the transformer reduces the line voltage and forms no new current. the transformer type welding machine has no moving part except a fan in air transformer. the transformer in which case the transformer is emerged in a thin oil commercially called transformer oil, the transformer welding machine in equipped with a regulator to control the current for the size of the electrode being by operator . the regulator may work on either of principle \
- For principles
- coil principle
- Magnetic amplifier principles

ii) DC Welding machine :-

         Dc welding machine consist of following parts :-

* Motor generator :-

         a motor generator consist of an electric motor (AC or DC) and a generator mounting on a common shaft welding current is supplied by a genrator which is driven by a motor. the open circuit voltage of the generator variess from 50 to 100 volt . special control are used to obtain proper current and volatge these control may be classified as
- a constant voltage type
- Constant current type
         in constant volatge type generator is variable resistance is put in series with an arc to regulate the voltage , this method is not preffered due t some loss of power in this way in a constant current type, the current does not change with the change in arc length . but the generator provides more volatge when the arc length increases and less decreases to the adjust the voltage demand , which depend upon arc length . this enable the operator to control heat by having almost same current supply

* engine driven generator ;-

         petrol, diesel, compressed air is used to drive the driven genertor , this is quite used area where electric power is not availaible and it is independent of external power supply , the engine driven generator is basically a source of electrical energy

* Rectifier welding machine :-

            rectifier is used to convert AC Into DC . rectifier welding mahine are essentially single or free phase Ac transformer type welding machine using a rectifier . this machine are also sometimes called as DC transformer power source

@ Equipments and accesories :-

- goggles
- Face shield
- Apron
- Hand gloves
- ELectode Holder
- Ground clamp
- Cleaning tool