Topic Welding/Design1

Designing rectifier transformer for welding with 26Vdc, 200Adc

Input parameters

Input Voltage 120V and 208V+-10%, 60Hz, sine wave
  Wire Al, round, single insulated, wound outside
Output Nominal DC output voltage 26Vdc, via one phase rectifier bridge and smoothing choke
  Nominal DC output current 200Adc during 1.5 minutes and 8.5 minutes pause
  Wire Al, rectangular wire, wound inside
Core Steel M45, alternate stacking, not annealed
Bobbin Type Single section tube for EE 200/3” or EI long 150/75
Design Insulation class H, max. nominal g temperature 165°C at ambient temperature 40°C, ventilated with 3 ft/s airflow
  Criterion of design Low price , high temperature rise

General rules

1. The welding transformers are normally forced cooled with airflow 0ver 3 ft/s

2. The welding transformers work in duty cycle operation mode and the winding losses are much higher than core losses. Due to this fact you can use cheap steel quality and relative high induction.

3. The welding transformers with Al wires are bigger, cooler but cheaper.

4. The welding transformers are always protected by a thermal fuse

Diagnose Input and Circuit CORE/BOBBIN/STEEL/CASE Ceneral Data