ac dc frequency?

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New here.  Wondering can anyone explain ac dc and frequency in terms of how it relates to welding?  Also why does stick welding perform better or penetrate more on dirty or painted surfaces than other forms of welding?thanks.
Reply:I would start with google and go from there, There are thousands of sites that can help you out and give you a great condensed version of what your looking for.
Reply:might try reading your text book for the answers.225NT bobcatAEAD200LEScott 125mm175, mm252 w 30A, PT225mm211, TA 181iHyper Therm 380, cut master 529100X & XX, Digital Elite6 Victor setssmith little torch, meco midget kalamazoo band sawsteel max saw evoulution circular saw
Reply:Originally Posted by jbmprodsmight try reading your text book for the answers.
Reply:AC is the change in voltage from negative to positive. Such as house power goes from 60V position to 60V negative and hits everything in between DC is a constant voltage say 12 volts and stays for example Frequency is how many times AC switches from peak voltage to peak voltage per second. There you go a quick and dirty description. That probably raises more questions than answers.Offering CNC Plasma cutting and welding projects.Follow me on facebook https://www.facebook.com/nobigdeal.fabSupport those that support WW.
Reply:Originally Posted by summermanNew here.  Wondering can anyone explain ac dc and frequency in terms of how it relates to welding?  Also why does stick welding perform better or penetrate more on dirty or painted surfaces than other forms of welding?thanks.
Reply:the simple of it for welding is (or what I think your wanting)  where the heat is in the arc, on AC it basically a heat that 50 % on the rod and 50% on the base material,on DC the heat changes so about 66% is on one place and 33% is the other, and since one can reverse the polarity of the welder, you can either focus the heat to the base metal or to the rod, (or that is what I had read at one time,) http://www.millerwelds.com/resources...calculator.phpDCEP: DC, Electrode Positive (reverse polarity) has the most weld penetrationAC: medium weld penetration (can be more spatter) DCEN: DC, Electrode Negative (straight polarity) has the least weld penetration
Reply:This may help.DC is like a battery.  Electricity flows in one direction only and there is no "frequency".  There's some debate about how electricity actually "flows", from + to - or vice versa, but it's not really important.  Just imagine it as electrons flowing in one direction.AC is like switching the wires back and forth on a battery from the - to + side and back again, really REALLY fast.  When someone says "frequency", they are talking about how how many times the electicity switches directions back and forth in a period of time, like in one second.  Your house electricity is AC, and the frequency is 60 cycles per second which is the same as saying 60 "hertz".  A "cycle" is going from + to - and back again.  So, in 1/60th of a second, the electricity flows out one of the little holes in the wall socket through a lightbulb and back into the other hole, switches directions, and switches back again.  All in 1/6oth of a second.  Kind of like swimming laps in a pool.How on earth does AC work if the electricity balances out?If you take a regular D cell battery and hook it up to a light bulb, it doesn't matter which side of the bulb is positive and which is negative.  It lights up either way.  If you could switch the battery poles really REALLY quickly, like at a rate of 60 hertz, then you'd have AC electricity going through the bulb and it would light up.  Actually it's really flickering from switching back and forth on the current, but it's so fast that the hot filament doesn't have a chance to cool down, so you don't notice the difference.Why does electricity work the same going one way vs. another?  It actually doesn't, and some devices need the electricity to flow only in one direction, but others don't care.  The ones that don't care are like grist mills - imagine a grist mill run by a donkey walking in a circle.  The grist mill doesn't really care which way the donkey is walking, it grinds the grain no matter what.On an AC welder, almost all the power coming out of the wall socket is used in the welding arc.  If you get a DC welder and hook it up to the wall socket, there are electric circuits inside the welder that convert the AC into DC.  But in doing that, you lose some of the overall power (I can't really explain why and there's two ways to do it in welders - inverters and rectifiers).Now, to welding.  For reasons that I can't explain, some welding rods and some metals can only weld or be welded using AC or DC.  And with DC, it matters which way the electricity is flowing.Why are stick welders better on dirt and paint?  They're not necessarily, it's all about the formulation of the coating.  For example, those ending in XX10 or XX11 are designed with a coating that reacts with the dirt and paint and allows the arc heat to work better.  Flux core wire is similar.  Depending on the formulation of the core "flux" in the wire, you can have flux core that works well on paint and dirt.Another advantage to stick and flux core is the burning coating (stick) and core (wire) creates a gas that shields the liquid weld puddle from oxygen and nitrogen in the atmosphere, so they work better when there's wind.  The coatings can also make the rod work better on AC, DC or DC reverse, or help the arc penetrate deeper, shallower, freeze quicker or slower, etc.  The unique "mix" of properties from a given stick are used to solve different welding problems.  A "fast freezing" welding rod would be particularly useful if you're welding overhead.  You want it to freeze before it drips down.Finally, it's not completely true that penetrating better is an absolute characteristic of stick welding.  Using the coatings, it can control how a rod works, but penetration is ultimately about how much heat you apply to the metal.  More heat / penetration is not always better, but that gets even deeper.Hope that helps.
Reply:RodJYou the man!! Thanks for a very informative ans.  And again, thanks to the others too..  P.S. if your a woman thanks too.Be nice and pay it forward.