On 20.02.17 13:37, Kirk Wallace wrote: > I'm a little surprised that this "What's It" didn't get more replies. > The pictures are of my Hobart TIG welder's spark gap assembly. The spark > gap is used in a circuit that adds a high frequency signal to the torch > to aid in starting an arc without having to touch the workpiece with the > electrode tip.
Ah, that's just about late 1800's technology. What a blast to still have a practical use for it. I can't help wondering, though, what it does for local AM radio reception? > Getting any workpiece material on the tip will ruin the > tip. I found a circuit of a DIY add-on arc starter here: > http://www3.telus.net/public/a5a26316/WelderPDFs_Pics/dbARC_START.pdf Did you wind the high voltage coupling transformer yourself? It doesn't look a lot like a catalogue item from here. I'm surprised there isn't a capacitor right in the output, with it connected across the welder output. (Based on zero welder expertise, admittedly.) > which includes spark gaps. I believe the space between the gaps sets the > output voltage. Back when I was a teenager, taking a more active interest in physics, we used to gauge the voltage of arcs by the rule of thumb "A kilovolt per mm, in dry air." I never had anything which could measure umpty kv to confirm the estimate. > I don't really know much about welder technology or welding. Acquiring > this knowledge has been on my ToDo list for many years. I have been > successful at doing some steel and aluminum welding with this unit, > but just enough to get a couple of jobs done. What I've read on Al welding has just served to convince me to stick with ferrous welding. And stainless seems easy to get wrong too. Then, even cast iron just bubbles when you aim an arc at it, so I settle for simple fabricating with plain steel, and building up the old mattock I've worn to a nubbin, grubbing 'orrible weeds, and digging ditches. Erik ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
