Recent content by diaz

Really bad isn't it. Guess that's why texaspyro has been measuring certain units as crapacitors. Should of set his test gear to old brick mode. Reminds me of a scart splitter box I got years ago, always felt like a quality bit of kit, had call to remove the cover one day only to find a...

Granted, that SCR I found on eBay is the same price as my bank of MOSFETS cost me. Good argument for going the MOSFET route, check Jiri's page here http://www.pittnerovi.com/jiri/hobby/electronics/welder/ it works, and this link (a new one to me) http://www.turtlesarehere.com/html/cd_welder.html...

If you want to weld and build a welder and save money all at the same time then be prepared that it might not turn out that way. For the time and money I have spent on my little project I could easy have bought a welder, especially one from China. But I like to tinker :) If you just want to weld...

Totally uncalled for. This thread is possibly the best internet source of information on this subject. Texaspyro (I am guessing that's who you were digging at) may not be going open with his design but he has given masses of information to this thread, and was no end of help when I PM'ed him...

The bus bars started life as 3mm copper (Obtained from good old eBay), then attacked with my milling machine to make them look as per the picture. Not the easiest things to solder. I got em warm with a hot plate then soldered each FET in with a big-ish 75w iron, warm work.

Cerium doped tungsten ordered. Pressure sensors ordered. Head scratching in progress as to how to make neat weld probes with replaceable tips and pressure sensors :?

Ah those funny looking things, think I even have a couple lying about somewhere, was never quite sure what they were until a couple of years back. So I have to ask what do your probes look like, any chance of a pic. I'm interested to see how you managed to cram it all it, I'm guessing from you...

Any chance of a link to such sensors ? Also would you care to spill a few beans about the cutting mode your welder has ? Do you just PWM the weld fets ? Presumably at a rate which the power supply can keep on top of ? What sort of frequency is used ? I know always questions :oops: Cam..

As always Texas words worth a fortune. Would you also care to share your weld material - to - weld probe material rundown ? Cam.

So how do you know what sort of weld energys and delays to start with for any given combination of metal, thickness, etc. Or is it a case of being a "proper" welder to know ?

You don't need to wait pyro, you already know the most part of it, and have a kick ass welder yourself. Seriously though thanks for the help.

Just a little update. IT LIVES ! Or at least it hasn't destroyed itself on a per weld basis as my previous attempts did. I will put some pics and the rest of the design files up when I think it's sorted-ish. I currently need to add weld energy settings, and capacitance measurement into the code...

I like the circular arrangement very neat thinking bigmoose. Here is what I plumped for with my 10 110,000uF caps, I went for a single layer pcb with 3mm thick copper :lol: It will carry ten IRFP4368's. On an amp for amp basis these costed out cheaper than IRFP2907's, this time bought from a...

Doesn't look good for the FET's Vgs @ 11.74v, Rds = 11.8 milliohms, measured using and old military spec earth bonding tester on 199.9 millohm range. Is it just me or do the leads look like two different metals scarf joined, brass and copper perhaps, can't imagine why one snapped on me. Doubt...

Reply understood, I am guessing you meant "on" instead of "of" in the above quote. That did throw me for a while. Anyway, does my design not ensure that as the voltage rises on the weld FET source pin that the gate voltage rises as well ? Provided I don't exceed Vdrive which is always kept 15v...