Welding machine types

[Flounders]

Im confused with stick welding machine types. Tell me if im right or wrong.

Transformers - 415w Welding machines that can be turned down to lower watts.

Rectifiers - A machine that changes the polarity AC to DC

Inverters - Not sure yet

Generators - Diesel or Fuel opperated welder.

Which ones are more common? Am I missing anything?

[Tensaiteki]

Originally Posted by Flounders

Transformers - 415w Welding machines that can be turned down to lower watts.

Not sure where you got the "415w" from but generally welding machines are rated in Amps, not Watts.

Straight transformers will only output alternating current (AC). This limits you to relatively few choices in filler electrodes (the actual "welding sticks").

Transformers can have either continuously variable output selection or tapped outputs that give you a few choices on the amperage output, tapped being most common. They are generally inexpensive, simple, and very rugged. However, they are electrically inefficient, heavy, and large.

Originally Posted by Flounders

Rectifiers - A machine that changes the polarity AC to DC

Technically they are called "transformer-rectifiers" as they are simply regular transformers that have rectification built on to the output. In most cases these machines can still output AC, if desired.

The addition of DC output allows for a generally smoother arc, better penetration and the ability to run a much wider selection of electrodes.

Aside from the DC capability, these machines have the same advantages and drawbacks as regular transformers.

Originally Posted by Flounders

Inverters - Not sure yet

While transformers use a large iron-core-wrapped-with-lots-of-copper-wire transformer to transform the input (line/mains) power (high voltage, low current) to welding power (low voltage, high current), inverters use smaller transformers and fairly complex electronics to accomplish the same thing. However, inverters are usually much smaller, lighter, and more energy efficient than regular transformers/transformer-rectifiers. Almost all of them provide continuously variable output selection

Inverters are usually more expensive than transformers, but their prices are constantly coming down. Furthermore, though more complex, their reliability and ruggedness is rapidly approaching that of transformers.

Most inverters for stick welding will only output DC, though there are more expensive models that will also output AC.

Originally Posted by Flounders

Generators - Diesel or Fuel opperated welder.

Technically called "engine driven" or "engine-generator" (to distinguish them from "motor-generators" which are an entirely different, and pretty much obsolete type of welder). Depending on the exact model, the can be fueled by gasoline, diesel, propane, or anything else you can run a internal combustion engine off of (some people have converted diesel powered welders to run on used cooking oil).

These machines can have either continuously variable or tapped outputs (largely dependent on age). Most will only output DC but a few will output AC as well.

Engine driven welders do not require that you have access to a power outlet, but they are generally noisier, more expensive, and more complicated to maintain that any of the other types.

Fairly recently, manufactures have begun producing engine-driven welders that are coupled with inverter technology to combine the benefits of both, though these are pretty expensive.

Originally Posted by Flounders

Which ones are more common? Am I missing anything?

That depends on where you are looking. They are all quite common, however inverters are rapidly replacing many transformer and transformer-rectifier machines. Which one you choose depends on what you plan to do with it, where you plan on doing it, and how much you are willing to spend.

[Jolly Roger]

Very good explanation. Just for information purposes I would like to add that a rectifier unit can be connected to virtually any transformer based ac machine such as Lincolns AC-225 to get dc output from it. I have only used a couple of these units and my experience has been that while smoother than ac they don't match those with the rectification built in.

[Flounders]

Thanks for that Tensaiteki!

Just wondering also if SMAW uses hand piece +

[Cruizer]

Originally Posted by Jolly Roger

Very good explanation. Just for information purposes I would like to add that a rectifier unit can be connected to virtually any transformer based ac machine such as Lincolns AC-225 to get dc output from it. I have only used a couple of these units and my experience has been that while smoother than ac they don't match those with the rectification built in.

Sure you can add a rectifier, though without a stabilizer it'll weld really horrible, 1 step forward and 8 steps backwards

[stickkid]

Tensaiteki: good job on the info, all this is explained in my textbook but it's nice to hear it from another source.
Man it would be cool to run a diesel engine driven welder off bio-diesel!

[smithboy]

One thing I see Tensaiteki say that a lot of folks use for shorthand is to refer to inverter vs. transformer. Like he says, they both contain a transformer, but the inverter machines use a very small one by comparison.

http://www.millerwelds.com/education...rticles31.html

The article above gives a bit of info about the difference between the "big transformer" machines and the "little transformer" inverter-based machines.

[Jolly Roger]

Originally Posted by Cruizer

Sure you can add a rectifier, though without a stabilizer it'll weld really horrible, 1 step forward and 8 steps backwards

My dad has had one on his old powerkraft crackerbox for near 30 years, not sure about the stabilizer, but it is a whole lot smoother than it was before we put it on. It still won't run 6010 worth a flip, but my Miller inverter leaves quite a bit to be desired with 6010 as well. It does it but it is no dialarc 250, nor is the crackerbox.