converting AC stick welder to DC

Discussion in 'General Electronics Chat' started by doug08, Apr 6, 2011.

  1. doug08

    Thread Starter Member

    Jan 30, 2011
    153
    2
    My current output is 34-35VAC. I added a rectifier of suitable amperage, and the voltage now reads 35VDC. I also decided to add smoothing capacitors (2) 37000uf - 40VDC electrolytics in series to raise the voltage rating to 80vdc, which lowers the capacitance to 18500uf. The minute I connect the capacitors to the circuit( ++, --), the reading on my voltmeter drops to zero. What is the deal with that? Never saw that happen before. I also plan on adding a 320v MOV on the Ac input and dc output. Do I need a reactor coil also? Or can I just get by on the capacitors/rectifier/MOV's?

    Thanks!
     
    Last edited: Apr 6, 2011
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,788
    945
    skip the caps altogether.

    The dc can have AC ripple on it. It doesn't cause any harm. AC goes to 'zero' volts and reverses polarity. As long as you have a positive(or negative) potential that doesn't change polarity or go to 'zero', then you are DC welding.

    Keep it simple.
     
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