62 ms·
DC is also much harder to switch than AC; the latter has zero-crossings which tend to extinguish any arcs that form, but DC will just keep going. Look at the DC
by userbinator 7mo ago
DC is also much harder to switch than AC; the latter has zero-crossings which tend to extinguish any arcs that form, but DC will just keep going. Look at the DC vs AC ratings on switches and you'll see a huge difference.
A nice demonstration:
https://www.youtube.com/watch?v=Zez2r1RPpWY https://www.youtube.com/watch?v=Zez2r1RPpWY
A more detailed explanation: https://www.youtube.com/watch?v=mQpzwR7wLeo https://www.youtube.com/watch?v=mQpzwR7wLeo
- mememememememo 7mo agoI take it welding is DC?
- elihu 7mo agoIt can be either AC or DC. Aluminum TIG welding uses AC, whereas you'd use electrode-negative DC for steel or copper. As I understand it, with aluminum you need the electrode-negative part of the waveform to transfer heat to the work piece, but you need the electrode-positive part of the waveform to clear out the crud that accumulates in the electrode-negative part. Often you set a lopsided duty cycle and use different frequencies depending on how deep you want the weld to penetrate. If you go to 100% electrode positive you tend to heat the metal rather poorly, but can turn the end of your tungsten electrode into a molten blob -- which is usually not desirable.