Turning an AC stick welder into DC

[Bill_C]

To Bill C. ..... A split phase system is not a two phase system. You are confusing polarity with phase, yes the waveform is inversed, but it is still in time. If you looked at the typical home service from neutral to each hot leg it will still be in time or phased regardless of the polarity. The typical home system is derived from one phase of a three phase distribution line. When it gets to your home via a middle tapped transformer it is still single phase just like the one phase is was derived from. The U.S. three phase system is three sine waves 120 degrees apart. If what you said is true we could have a very interesting induction motor in our homes, but we don't. We have split phase motors depending upon a start winding and a run winding. As far as the topic at hand, you can build a bridge rectifier (four diodes) for the DC welder but another component that most DC transformer welders have is a reactor for ARC stability.

I'm in complete agreement, so perhaps you've misunderstood me or I typed something too hastily. The terms two-phase and split-phase have been incorrectly interchanged at times, (perhaps I did incorrectly state two-phase in my first post when I should've said split-phase), but yes we have a split-phase system in our houses, and yes 3-phase is 120 degrees out of phase.

The polarity of the two wave forms are indeed inverted, and thus they are 180 degrees apart. (I suppose we could quibble over whether the two wave forms are called phases, I would say they technically are phases but they are still 180 degrees apart.)

 

[RWolf]

Gemini- I do apologize if I came across sounding all knowing. We both have our experience and knowledge and now hearing where your's comes from I understand your statement directed toward me earlier. I see that your's is based on industrial setups where mine is more commercial/residensial (sp). I have basically no knowledge when it comes to industrial setups. I do know what works at my level and have been doing it safely for many years. Again I apologize for ruffling your feathers.

 

[gemini5362]

Gemini- I do apologize if I came across sounding all knowing. We both have our experience and knowledge and now hearing where your's comes from I understand your statement directed toward me earlier. I see that your's is based on industrial setups where mine is more commercial/residensial (sp). I have basically no knowledge when it comes to industrial setups. I do know what works at my level and have been doing it safely for many years. Again I apologize for ruffling your feathers.

Rwolf no need to apologize. I probably worded my first post in reply to yours too strongly. I know better than to make posts when I am sleep deprived. I have a tendency to worry about the novice that reads posts from experts in a field. Experts make things sound easy because to them it is. Welding is one of the things that makes a good example. To hear the experienced welders talk, and then to see some of the things they build it looks easy. If I could make a bead look half as good as some of the ones I see posted here I would be on cloud nine for a week. Electricity can be taken that way also. If you read one of Pat_g's recent posts he went out put a new sub pannel in his barn, ran power to this and to that. Sounds like no big deal the way he describes it and it probably wasnt for him. He also has some degrees to back that up and a lot of experience. I would hate to have someone inexperienced read what pat has done and say well this did not seem to be that hard and start putting in new sub panels and have a wiring error or not ground the panel correctly or something like that. There have been times where I have made absolute statements and someone has come along after me and pointed out that what I said is not correct every time. That is what I was attempting to do with your post but I just did it badly.