High amp arc?

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If an arc is produced by voltage, how does a high amp low voltage stick welder keep an arc?
Reply:This should explain. http://en.wikipedia.org/wiki/Electric_archttp://en.wikipedia.org/wiki/Arc_lamphttp://en.wikipedia.org/wiki/Arc_weldinghttp://wiki.answers.com/Q/How_much_i...n_electric_arc
Reply:Voltage may create the arc but current makes the intensity of the arc. If you put a test light across a car battery you may not even see an arc because the current flow is so low. No say as long screwdriver is allowd to cross both terminal (which I don't reccommend trying) you'll get a large arc because the screwdriver blade will carry nearly the full current that the battery can supply. In both cases the voltage is low.Tough as nails and damn near as smart
Reply:Yeh in real general terms it's really a matter of total energy when speaking of creating an arc. I could create a crude arc with 40 volts and 100 amps with a given electrode (not welding yet) or 400 amps and 10 ten volts, same energy.  However there are so many instances in our daily lives where it always seems to be the voltage as the instigator of the arc that we tend to automatically associate arcs with high voltage. Not necessarily true. Also remember "high" voltage is a relative term and not quantitive. Welding is unique in the fact that we have discovered by controlling the voltage, controlling the amperage, controlling the current density (sizing the electrode just so-so) that we can set up a scenario where we can create and control a molten puddle. Miller has a nice little tutorial for anyone who wants to dabble into what goes on in the basics of welding world instead of trying to fuss with electrical theory and correlate lightning bolts to a lincoln buzz box.  http://www.millerwelds.com/interests...ndamentals.pdf"The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Would it be correct to say that the disintegration electrode reduces the resistance of the air?this diagram shows what I am talking about:http://en.wikipedia.org/wiki/File:SMAW_weld_area.svg
Reply:Originally Posted by ziper1221Would it be correct to say that the disintegration electrode reduces the resistance of the air?this diagram shows what I am talking about:http://en.wikipedia.org/wiki/File:SMAW_weld_area.svg
Reply:but why will an electrode only create an arc from an inch away if it has been struck? An electrode that is an inch away will keep an arc, but an arc cant be started from an inch away?
Reply:Originally Posted by ziper1221but why will an electrode only create an arc from an inch away if it has been struck? An electrode that is an inch away will keep an arc, but an arc cant be started from an inch away?
Reply:OK, got it.
Reply:To create an arc, you have to break down the airs ability to create resistance. Once air is hot, and emitting light, it can no longer stop the flow of electricity. The metal particulate is just a complication. What most people do not know is that when you don't see an arc jump across the points in a light switch in your house. Points that are 3/32nds of an inch apart. It is because the electricity is connecting to the opposite point, 120 times a second. However the air above the point receiving the voltage, is raising in voltage enough to stop the flow of electricity. Back and forth back and forth that little switch works to stop electricity. Only electricity stops electricity. Insulators do not stop electricity. The insulator must become charged like a battery, in order to stop electricity. This is Benjamin Franklin's work that started America. Insulators do not conduct a large amount of amperage. However they are always conducting small amounts of electricity when charged. This shows how a diode or a battery stops electricity. http://www.Rockwelder.com/Flash/Elec...icityflow.htmlYou can stop the power from a 400 amp welder, with ten nine volt batteries in series. Even though the batteries put out less then 90 watts and the welder will put out 18,000 watts. All you have to do is match the voltage. That is what a diode is a tiny, tiny battery. That you charge and then it repels incoming voltage in one direction.With an oscilloscope I can visually see the charge enter the diode. One day when you are welding and your shirt is getting a little damp. Connect the ground clamp to something metal, electrically touching the cement floor. A railing definitely works. Lay on the floor, and then touch the arc rod with one finger. You gotta love that. Ha-ha. Even plastic insulating material will do that too. The side of a van will do that too.        Sincerely,             William McCormick
Reply:And be careful not to walk under a hi tension line with your tin foil hat on.Might just cook your brain, like some of our other illustrious posters.Man, William, you should be writing science fiction rather than posting on a welding board.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:I don’t know where this guy in your video got his training? Obviously he never has encountered a Wheatstone Bridge.  http://en.wikipedia.org/wiki/Wheatstone_bridge
Reply:You should put down the books and try the real world, SundownII.        Sincerely,             William McCormick
Reply:I hate to say, water has electricity in it. Don’t let Will get wind of it.
Reply:That is a circuit to isolate the galvanometer from high voltage. High voltage that might be present in what you are testing with an ohm meter. Also good for not charging a transformer up, while you are testing for a short to ground or continuity through either coil. Big motors too. When you lay on your back with a wet "T" shirt and touch your welding rod, you become part of a capacitor. And you know it. Ha-ha. Cement is not capable of giving you a reading on an ohm meter, an inch away from a metal object embedded in the cement, even using a very sensitive ohm meter. So by all logic you believe that you should not get a shock from the cement, because your welder is at best outputting 90 volts. But you do get a shock through your back if you are laying on the cement in a damp "T" shirt, and you touch the welding rod in the electrode holder. The reason is the square inches in contact with the cement. The water creates a dielectric barrier between you and the cement. And between the fibers of the cotton "T" shirt. The formula is like the formula for a capacitor. http://www.rockwelder.com/electricit...apformula.htmlCheck out the title on the page.        Sincerely,             William McCormick
Reply:Horse apples! Too many variables, how wet or dry is the cement below the surface. Pure water is not conductive, but there is not much pure water around. What about the salt on your skin making the water conductive in the cotton? And to have that capacitor effect, both plates in the cap MUST be conductive, one being you and the other plate the cement which may or may not be conductive, and if conductive is a path to ground.Last edited by transit; 03-22-2010 at 12:13 AM.
Reply:Dry cement reading zero continuity across an inch of cement, with the most common most sensitive ohm meter you can find. Before you attack I have no doubts. But check it out if you do not believe me, before you attack further. I have gotten it in attacks, installing AC evaporator units. I leaned up against the old brick, cement coated chimney with a coat of paint on it, and got a good one with a wet "T" shirt. I got it between the chimney and the evaporator unit.I have gotten it from a van with a running gas welder in it, on a rainy day. I had a full one piece Carhart suit on. It was just getting wet, and I tried to squeeze through the van and the railing I was welding. That was just down right funny. It looked like I was having sex with the railing. Ha-ha. The homeowner is probably still afraid of me coming back. She was watching us right there by the door and stoop, the railing was on. She must of thought I thought she was something else. She was pretty though. Or that I loved my work perhaps a little too much. Ha-ha. The van was painted. Once by the factory, once by the boss with a roller, to hide old Grumman lettering. I have gotten it laying on the ground doing the underside of steel handicap rails a few times. You know it. It is surface area that makes the difference.        Sincerely,             William McCormick
Reply:Don't go out without your tin foil hat. Ha-ha.       Sincerely,             William McCormick
Reply:those multiple instances of shock therapy explain a whole bunch.