/diy/ - Do It Yourself

[Rectifying a DIY welder No.1518263]

I've built a MOT arc welder. It works fine for the most part, but I wanted to rectify it.
Except I regulate it at the primary (which is retarded but not entirely dysfunctional apparently) and I was wondering whether it would even really work.
I'm using an SCR regulator, so I imagine the resulting sine wave looks like shit (I blame that for the amount of spatter in my welding, together with the chinkshit rods.)
What would it even look like after rectification? I don't have an oscilloscope yet...

[Anonymous No.1518274]

>>1518263
>What would it even look like after rectification?
Look on YouTube for converting AC only welders to DC units.
They add chokes and capacitors as well as rectifiers.
The smoother the DC is, the smoother it welds.

[Anonymous No.1518277]

>>1518263
>Except I regulate it at the primary
You will be putting half wave rectified sine waves on the transformer primaries. Which will be inefficient, might saturate the transformers and overheat them. And the secondary will still be crap waveform AC.

If you want DC output, you have to rectify the secondaries.

Also, from your pic, it appears that you are placing the transformer secondaries in series. Why? That will increase the welder voltage output, but not the current. Is that what you want?

[Rectifying a DIY welder No.1518282]

>>1518277
>You will be putting half wave rectified sine waves on the transformer primaries. Which will be inefficient, might saturate the transformers and overheat them.
As I said, it works, but the welding characteristics leave a lot to be desired, which is why I'm looking into the prospect of rectifying it.
>If you want DC output, you have to rectify the secondaries.
Well, since rectifying the primary would render the transformers into useless chunks of steel, then yeah, I guess?
>it appears that you are placing the transformer secondaries in series. Why? That will increase the welder voltage output, but not the current.
Since each TF outputs about 15VAC, that was the idea.

[Anonymous No.1518341]

>>1518277
>>1518282
On second reading I think we misunderstood each other.
- I regulate the welder using SCR on the primary, sending pic related into it.
- This understandably results in identically fucked wave on secondary.
- I wanted to know whether building a rectifier unit would even work with a chopped wave like that.

[Anonymous No.1518343]

>>1518341
Forgot pic related.

[Anonymous No.1518347]

>>1518341
>I wanted to know whether building a rectifier unit would even work with a chopped wave like that.
>>1518343
Yes, but would require MUCH more filtering to make it good for welding.
What about powering different combinations of transformers to select power?