1. LC Engineering

2. Stages of combustion Primary Combustion – Acetylene & Oxygen burn in the primary combustion zone to give off Carbon Monoxide and Hydrogen. C2H2+O2 2CO+H2 Secondary Combustion – oxygen is sucked in from the weld pool and is burned with Carbon Monoxide & Hydrogen to give off Carbon Dioxide and Water vapour. CO+H2+O2 CO2+H2O

3. The Oxidising Flame This is a result of excess Oxygen. Approx 1.5 parts oxygen to 1 part acetylene. If used with steel the excess oxygen would contimnate the joint, so it is used for copper and some bronzes. It has a temp. of about 3500ºC max temp zone inner cone secondary combustion zone

4. The Carburising Flame This is a result of excess Acetylene. Approx 0.9 parts oxygen to 1 part acetylene. Has a temp of approx 3150ºC and is used for welding alloy steels and aluminium alloys max temp zone inner cone secondary combustion zone C Acetylene feather

5. Transformer/ Rectifier Transformer Rectifier Dropping Voltage means current increases current, which is needed for welding. There is a primary and secondary coil. The number of windings on each coil controls the output current. Primary 100 Turns and 220V and 10A Secondary 200 coils = 110V & 20A The Rectifier converts AC to DC. It uses 4 diodes arranged in a diamond shape. 2 diodes conduct in each half- cycle. The capacitor ensures a smooth output.

6. Transformer/Rectifier

7. MIG/MAGS Metal Inert Gas/Metal Arc Gas Shielded. Semi-automatic Process Consumable Electrode fed automatically. Argon gas protects the weld pool like a flux. No slag produced. Suitable for steel. Argon Gas Wire Feed Power Plant Welding Gun Electrode NOTE: CO2 welding is a form of MIG/MAGS

8. TIG/TAGS Tungsten Inert Gas Non –consumable Electrode. Filler rod used. Argon gas protects the weld pool like a flux. Suitable for Aluminium & Stainless Steel. Filler Rod NOTE: Label the diagram using MIG/MAGS as a reference.

9. A Transformer steps up and down the voltage to set welding currents. The Rectifier converts AC to DC using a series of diodes.

10. Resistance Spot Welding

11. Resistance Seam Welding

12. Submerged Arc Welding