What is the relationship between the input power and output current of a small household welding machine?

1. Output Power (Welding End) = Output Current (A) × Arc Voltage (V) The arc voltage for household manual welding is generally fixed at 20-30V (25V is used as a reference for conventional welding).
For example:
Output Current 100A → Output Power = 100 × 25 = 2500W (2.5kW)
Output Current 200A → Output Power = 200 × 25 = 5000W (5kW)

2. Input Power (Maintenance End) = Output Power ÷ Conversion Efficiency The conversion efficiency of inverter DC welding machines is approximately 85-90% (85% for household models),
while AC welding machines are only 60-70% (not recommended for household use). Using the examples above:
100A Output → Input Power = 2500W ÷ 0.85 ≈ 2940W (≈3kW)
200A Output → Input Power = 5000W ÷ 0.85 ≈ 5880W (≈6kW) 250A Output → Input Power = 250×25÷0.85 ≈ 7350W (≈7.4kW)