need help igbts welder

Well, you do not have to deal with paralleled igbts (unless you want to go above 200A). I do not think that that person actually go to having a working welder.

i have 4 and only need to use two of them and they take 400amps for 1ms note my welder gos to 225A and the one i got this from does weld with it hears what he sad from his web site (Just for interest the devices used in the Alpa test version of the unit were IRG4PC40F (600v 27amp, these will handle 49 amps in pulsed mode ! 4 pieces were parralleled for each section of the H bridge. I later switched to a higher current device G30N60B3D which is good for

witch capacitors would br best in it?????

I would suggest Cornell Dubilier snubbing capacitors, like their series 943.

ok, and what abouth the 470nf caps and the ones on the igbts ?? thears more of this circuit print it out its 20"x40" its big :-)

are those on IGBTs or on the IR2110 gate driver?

IR2110 gate driver C18,17,19,20 are the 470nf and the 1nf caps on the igbts ok;-)

for

diode

You need to read the IR2110 datasheet. I am surprised that you say that caps across IGBTs are 1 nf. There is also an application note explaining some issues if using IGBTs to make inverter welders.

with

devices

for

diode

i did read the application notes and some more and they both say something else, and the caps are on the driver board for the igbts the one that are in the circut that i am asking abouht are C1 to C16 in the circuit the application notes say not to use them then one site says to use them that why i need help on this as take them out or not??? the igbts are the same ones that you had on your first setup;-)) from the same one on ebay i know the caps C21,C22,C23,C24 are to stop voltage spikes from takeing out the igbts

for 1ms

with

devices

parralleled

good for

diode

so

I used different driver boards by Semikron. (also off ebay). These are very good. They did all I wanted without messing around with complicated schematic. All I had to build as an oscillator.

Application notes (can be found somewhere on my site) explain how to calculate snubbing capacitor capacitance. You also need a brief period when both sides of the bridge conduct.

for 1ms

with

devices

parralleled

good for

switching diode

) so

i have the notes from your site. i just dont get what the notes say and this has a what new welders have " max current ,start current ,weld frequency ,end current ,pulse frequency and gas on and off time ,duty cycle ... the one that did it up used cmos, ttl chips.. first time doing something with this many amps so you can see why i need the help i dont whant to blow up the igbts

weld with

devices

parralleled

good for

switching diode

would it be safe to put them in to the circuit for now or should i take out some stuff and should i use film caps on the driver board the data sheet for the IR2110 on what type of cap should be used as to film or ceramic cap for the 470nf=.47uf and the 1nf=.001uf

i have the notes from your site. i just dont get what the notes say and this has a what new welders have " max current ,start current ,weld frequency ,end current ,pulse frequency and gas on and off time ,duty cycle ... the one that did it up used cmos, ttl chips.. first time doing something with this many amps so you can see why i need the help i dont whant to blow up the igbts would it be safe to put them in to the circuit for now or should i take out some stuff and should i use film caps on the driver board the data sheet for the IR2110 on what type of cap should be used as to film or ceramic cap for the 470nf=.47uf and the 1nf=.001uf

would ac film suppression caps work for the out put to kill the spikes ???? and for the rest should i use polyester film caps i have been looking at wima caps ????

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You have not stated many details about your project, and it is just about time.

Are you trying to make a inverter welder? Are you redoing an existing welder? What do you want to accomplish?

The first thing that I must say is that if you have the brains and skills necessary to figure out how to make such a welder from scratch, you would be better off buying a brand new Miller welder for several thousands of $$ and using your skills to make money elsewhere. That said, if you like to have fun inventing stuff, there is nothing wrong with it.

So... You need to give some details of where you are and what are your intentions.

I think that I would do this work in stages, not least because you would be learning as you go, moving from one working prototype to the next. Rather than assembling some contraption that surely would not work, and then realizing that you forgot something at earlier stages that cannot be easily corrected.

That's a computer programmer's approach.

The first stage would be to make a DC power source with no bells and whistles. (that itself is a big task). Just a basic stick welder.

If you get here, it would already be a huge accomplishment and you would be able to do a lot of real life welding with that.

If you get thus far, a sensible next step would be to make a high frequency arc starter. (could be easier to just buy one, a respectable choice)

Then, you can move on to make a basic TIG welder, with a two stage pedal (one stage for gas control, another for turning on arc).

The last step, the inverter, is very independent from everything else and can be done much later. And can be skipped altogether.

Really, most real life welding can be done without the inverter.

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yes i am trying to make a inverter welder i have a stick welder and have 4 diodes on it to get dc with 2 big cap, and did up a HF starter for it and have a tig torch and have done some welding with it but the HF starter will not work with the welder on ac and i have the igbts i did up a foot pedal that turns on gas and the HF starter...... i need to get this done becoz 30amps will go throu sheet metal and i like doing this and hears the site that has the circuit for this

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forgot this i did have in mind to use the monolithic function generator XR-2206 but i found that circuit and plan to use it and it will give me what i need

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plus it would cost 1.082.00$$ for a tig welder that would not weld Aluminum tig for aluminum would cost 1,338.00$$ cost so far welder free tig torch witch is water cooled 60.00 igbts 40.00 caps and neon transformer 15.00