Frequency depends on whether the set has the ability to adjust it, if that's the case anywhere between 20hz to 300hz. Otherwise would of thought it will be 50hz
Voltage is manufacturer dependant. Type of power source; Transformer/Inverter is also a factor as well I use 3 sets and I seem to remember they are all different.
i wanted to assume that it was 50hz for a fixed one but wanted to check, as as you suggest ive seen variable ones.
i also knew you were going to say manufacturer dependant, i just need a rough guid line or are they substantially different, for instance 1 is 12v and another is 40v or are they all a similar figure.
i am wanting to know as i have been after an alu capable tig for ages now but havent got enough disposable income to splash out £4-600 for one.
i am HND qualified in electronics and electronic design and we covered inverters, swithcmode psu's etc at uni, so was going to attemt to make one. a dc set is very straight forward but obviously the ac is a little more tricky.
its only going to be a diy, budget thing, more of a project really.
as its going to have dc functionality is the dc open circuit voltage the same as the ac?
Sounds like a cool project. Are you planning on using IGBTs? what are you planning to drive them with? do you have a processor in mind? Do you have any example code of square wave/sine wave PWM sequences or are you planning to start from scratch?
i was planning on using FET's, purely as i have some reletavely high powere ones at home meaning i wont have to buy anything, ive looked into IGBT's but never really done much with them.
i will post likely be controlling them with a PIC Micro.
no i dont have any example code, but the PIC's a aloready have have got PWM facility built in so no doubt there will be something available, but id rather give it a go on my own first, then checkout what other people have done.
after i get a first prototype working, i will look into pre and post gas flow etc all controlled via the pic.
I've written some PWM DC motor control before, the PWM function of the uC was up to the job, the biggest issue was getting the main cycle to run quick enough to get the variable PWM modulation quick enough to produce a decent output. Should be less of an issue at 50Hz ish.
Good luck, sounds like an interesting project, I'll follow it with interest.
ive done bits with pic but never got involved much with th pwm function, ive done quite a bit of reading on it as i wanted to control some RC servos for a project i had, but never got around to it.
i was / am going to build an all alu tube baja type buggy with a 2 stroke engine in it, got all the tubing etc, almost everything i needed, bought a alu brazing kit off ebay, but failed at it, half the reason i want an ac tig to be honest.
rodof , thanks for that link I have downloaded all the circuit diagrams before some enterprising person decides to start charging for them like they do for wind gen panels and 3ph convertors. I could see myself building a TIG machine using that design or maybe not , it would take me 6 months but its all there for anyone wanting to try and as he says you wont see another one like it and I take my hat off to him . I recently purchased a duff old 450 amp 3ph TIG machine and its got all the necessary stuff for arc starting so could probably plumb this into the design to save one stage and probably theres other stages could be done with commercially available boards / equipment , is the guy who started this project still active as he did this in 2006 so would be good to see if he has refined it any and to see a few welds done with it , maybe he is already a member of this forum ?