Ac waveshapes

[Chris Stevens]

I don't think so. They don't give square wave on inverters because they can't produce a transformer type sinius wave. I have used transformer welders and yes some of them are lovely to weld with. Inverters with there adjustable freq and advanced square waves make life easier on thin gaged and fillets than fixed Hz sinius waved transformers. Yes it's done regularly on transformers and they are very capable smooth machines. I could join 2 coke cans a lot easier on an inverter than a transformer

I think you hit the nail on the head there Richard.................certainly inverters are superior for certain types of welding, and the adjustability is a very useful feature. Not sure if they are ever going to rival the butter smoothness of a good transformer or the long term reliability, ease and low cost of carrying out any repairs needed though? My ancient L-Tec has only needed a set of HF points, which are exactly the same as Miller and only cost £10!

 

[Piero]

With an inverter type tig set.

What setting would you choose (that the transformer type don't have) to weld thin stuff like yr coke can example.

Wave form. Hz . Freq etc.

No need to go into post and pre flow or slop up down etc

 

[Chris Stevens]

Never messed around trying to weld coke cans myself, but a m8 of mine has a small model plane made of welded coke cans hanging up in his workshop.

 

[Piero]

You just got to get a photo of that and up load it

 

[Chris Stevens]

I will next time I am round there. All done with vintage transformer set though!

 

[hotrodder]

As Technic Al said square wave (and other waveforms) varies some between different manufacturers even though they all use the same names/basic shapes. I would've thought an inverter should be capable of doing a very good impression of sinewave but they don't bother because then you'd need constant HF to keep the arc lit/relight it every cycle? That's why the sinewave from inverters is still typically a bit 'harsher' than even a squarewave transformer set that still needs constant HF?

The entire point of squarewave is increased efficiency. A true sinewave spends most of it's time moving slowly and smoothly between peaks, square the waveform off some and the arc spends more time at the peaks. An inverter can switch faster so it's squarewave can be more 'square' than a transformer based machine so even more time at the peaks and you no longer need constant HF. More time at the peak of the waveform = more EN and EP time. Don't need all that EP so can bias the arc more to EN to put more heat into the work and less into the tungsten for more efficiency
Triangular waveforms are supposed to keep the fast switching but make welding thin stuff easier. Easier is a subjective thing and like everyone else i just find it annoyingly harsh and while it can make properly, stuuuupidly thin stuff a nats easier it doesn't make enough of a difference to put up with the harshness and arc noise

None of the different waveforms or being able to adjust AC frequencies or having pulse or being able to pulse at hundreds of Hz lets me do anything that i can't do with a basic transformer machine. It does let me do somethings more quickly and sometimes make jobs a bit easier... for example being able to focus the arc more to produce a narrower weld can make life easier if you have to weld stupidly close to a bolt hole

 

[Richard.]

I agree the wave shapes really make too little of a difference for me to worry about switching them and I just keep it in square for everything. AC frequency though is another thing. I adjust that a lot from joints and although I'm sure I could manage if it was fixed in a usable all round figure (80hz ish would be OK) it makes things waaaaaaay easier having that adjustment.

 

[Chris Stevens]

I get the feeling that in reality many of the enormous advantages suggested for inverter over transformer are marketing hype! Inverters are cheaper to make, can be put together with unskilled labour, cost less to ship, and I would guess mean higher profits for manufacturers? Suggestions that Chinese inverter welding sets are being used in heavy duty industrial production situations, and work better than Miller machines, clearly need to be taken with a very large pinch of salt, and maybe so do the perceived advantages of all the bells and whistles on almost all inverter welding sets on the market today?

 

[Piero]

Inverters ain't all bad.

That's a little negative veiw.

How would you transport a transform based tig set to site day in day out and to different sites.

How would you get 220 amps from a 240v supply.

How would you tuck a large transform based tig . Neatly away in a small shed or workshop if space is sparce

The list goes on.

 

[Chris Stevens]

I didnt suggest for one minute inverter welder sets are bad (have an MLS2300), just that the perceived advantages related to things like waveforms etc should maybe be looked at more objectively?

The advantages outweigh the disadvantages for sure, but there really isnt anything welding wise you can do with an inverter you cant do with a transformer, although it might take a bit longer with the old tech.

 

[Richard.]

I get the feeling that in reality many of the enormous advantages suggested for inverter over transformer are marketing hype! Inverters are cheaper to make, can be put together with unskilled labour, cost less to ship, and I would guess mean higher profits for manufacturers? Suggestions that Chinese inverter welding sets are being used in heavy duty industrial production situations, and work better than Miller machines, clearly need to be taken with a very large pinch of salt, and maybe so do the perceived advantages of all the bells and whistles on almost all inverter welding sets on the market today?

Try plugging a transformer into a 13 amp socket. Also this thread has nothing to do with Chinese machines vs Miller. Both inverter and transformers have there place in industrial environment. I'm not one for gimmicks and machine bells and whistles, arc stability is far more important for me and a good inverter can offer this as well as a good transformer. My old magicwave 2000 would keep up with a good transformer in this respect day in day out. And it would put out a solid 200 amps from a house hold supply, can be carried in the back of a small hatch back and was still running well after 17 years old. There are advantages to both types. My mls has some huge shoes to fill.

 

[Chris Stevens]

The idea that a Chinese inverter set is better than a Miller, seems to be an idea which is linked to advertising more closely than fact, in the same way that inverter bells and whistles are often perceived to mean that they work more effectively than transformers.

My MLS is certainly easier to use for some jobs than my transformer, but the fact that its current technology, doesnt in my view automatically make it superior in terms of function to the earlier stuff.

 

[Piero]

I hate to be the one to say.

But It makes more sense to keep this thred on its topic of AC waves shapes.

I am guilty of adding my bit. But the topic seems to be slipping to if inverters are better than transforms

 

[Richard.]

I didnt suggest for one minute inverter welder sets are bad (have an MLS2300), just that the perceived advantages related to things like waveforms etc should maybe be looked at more objectively?

The advantages outweigh the disadvantages for sure, but there really isnt anything welding wise you can do with an inverter you cant do with a transformer, although it might take a bit longer with the old tech.

I am a big fan of transformer type plant and yes they were used for years by skilled guys welding anything and everything. I'm also a huge fan of inverters and without them 90% of the hobby welders on this forum would not be owning tig welders. They make life easier and offer solutions to increase productivity with some of the features they offer. I agree with hotrodder you don't need those features but ones such as AC Frequency for narrowing arc width and a DC pulse for thin gaged stainless (particularly outside corners) reduce heat input and distortion, if they help then it's a good thing. Wave shapes are not so useful IMO and the tiny advantages from changing them doesn't out weigh the pros IMO from sticking with a good square wave. I hate the tri wave as its never given my thin Alu welding any advantage from what I can see and the added row (even with ear plugs) is annoying. Sin wave is ok but it tends to spread a bit more but offer a fluffy arc I find. It's the most bearable regarding the noise produced but square is the one for me and it's a nice square wave offering on the unit I have now. Marketing nowadays tends to be focused on the tech that the others don't have. Kemppi has that micro tac thing, Miller has that fancy advanced wave, fronius have the job modes and a fancy wave pattern, esab has the micro pulse and I am sure there are loads of others with there own little additional things and patents to make us believe it's better than the competition. I'm not fuzzed about stuff like that but I do use some inverter type basic settings a lot simply cos they are there to use and they work to make life easier which is what it's all about.

 

[Richard.]

The idea that a Chinese inverter set is better than a Miller, seems to be an idea which is linked to advertising more closely than fact, in the same way that inverter bells and whistles are often perceived to mean that they work more effectively than transformers.

My MLS is certainly easier to use for some jobs than my transformer, but the fact that its current technology, doesnt in my view automatically make it superior in terms of function to the earlier stuff.

Chris seriously you need to let this Chinese thing/problem that you have go. Why do you feel the need to chuck that in every where and what has it go to do with this thread. If you don't like Chinese the answer is simple, don't buy anything made in China and don't go to China.

 

[Chris Stevens]

Chris seriously you need to let this Chinese thing/problem that you have go. Why do you feel the need to chuck that in every where and what has it go to do with this thread. If you don't like Chinese the answer is simple, don't buy anything made in China and don't go to China.

No problem with Chinese, have got some Chinese made bike engines, and they seem very well made for the money. Not comfortable with the idea of deliberately misleading advertising though, which I think may in many cases leads to inexperienced end users paying a higher price for equipment which isnt as well specced as less costly alternatives.

 

[Richard.]

Chris people (generally) ain't wallys and if they budget 3k for a welder they will know that a Miller at 3k is going to be superior over a unit at £500. If they budget £500 they can't afford a Miller so it doesn't really matter what the advertisers say. Call trading standards if it bothers you that much. I'm not a fan of cheap nasty gear myself but I'm not bothered how advertisers flog it tbh. I've got better things to concentrate my thoughts on. We are all in a world where we know we get our money's worth or we complain.

 

[wheresmejumper]

I must have missed the post claiming chinese inverters were better than millers?

 

[Chris Stevens]

I must have missed the post claiming chinese inverters were better than millers?

Not a post on here, its an advert on the inverter seller web site........................lol

 

[wheresmejumper]

Whose advert?