Nice! I'd have to dig out my old physics books to find out what the effective resistance would be of an ionised path through argon. Could well be low enough that the actual effect on any 'normal' welding distance variation is in effect pretty much 0. Quite interesting though as many docs and videos...

Very nice to see the V/A graphs :!: Eg. you can clearly see the spike in voltage right after the crossover point where the arc need to re-establish (higher resistance) even though HF is helping to keep the ionisation. Once the arc path is there the voltage drops to the base welding level as the pat...

Very nice to see the V/A graphs :!: Eg. you can clearly see the spike in voltage right after the crossover point where the arc need to re-establish (higher resistance) even though HF is helping to keep the ionisation. Once the arc path is there the voltage drops to the base welding level as the pat...

Hi Martin, There may be an actual imbalance between the EN and EP currents due to partial rectification. What is the nature of the common mode noise? Thanks for your efforts - very interesting! Jack Hi Jack, I don’t know what the nature of the common-mode noise is? How would I go about finding out ...

Hi Arno, I must thank you: I finally decided to get a Pico TA057 differential probe. Now, it all makes sense: there is no puzzlement when overlaying voltage and current. On all the tests below, I had the AC Balance set at zero, i.e. 50% electrode negative and 50% electrode positive. However, when I ...

Yeah.. I was kinda expecting the HF to be a headache there as far as voltage measurement goes as that basically indeed induces massive voltage spikes. Thanks for trying anyway! Bye, Arno. I’ve not given up yet: I’m looking at differential probes, because this isn’t the first time I’ve wished I had ...

Further to my last post, I also tried using (a) a capacitative automotive HT lead pickup, and (b) and inductive pickup. The HT pickup similarly over-ranged on the maximum setting (just like the x10 probe), whereas the inductive pickup did show an AC voltage at the same frequency as that of the curre...

Yeah.. Because the power source is being actively controlled and generating the actual 'signal' in an inverter welder and we're not looking at a traditional 'dumb' A/C source (like a bare bones transformer just 'translating' the incoming A/C sine to a different/lower voltage but doing nothing else)...

One thing that's always interesting to see would be an overlay of the amps with the weld circuit voltage on the same graph with these kinds of A/C or mixed curves to see if perhaps the volts are shaped like the described functions or not at all. As inverter machines (try to) control the various com...

I'm using a 200A/2000A Pico TA167. My 'scope is a PicoScope. I also have a Fluke i30s, which is good up to 20A RMS. I have a Fluke i1010 which will handle the current but has neither the bandwidth nor the basic accuracy. It has sufficient to see what is happening though. What I never seem to have i...

I thought it might be useful to look a little closer at the shape of the sine wave, the trapezoidal wave and the square wave, shown in that order below, just to be more aware of how much more energy is going into the workpiece with square wave per unit time: sine wave up close.jpg Trapezoidal up clo...

I also found and read Part 2 of that Everlast description: Yes, sorry - part 2 discusses the advanced pulse function. I meant to ask what clamp meter you are using now. Thanks Jack Hi Jack, I'm using a 200A/2000A Pico TA167. My 'scope is a PicoScope. I also have a Fluke i30s, which is good up to 20...

Thanks for the images. The Everlast description (also same as R-Tech) describes that but there are no images. Your images complement the Everlast description. https://www.everlastgenerators.com/blog/pulse-versus-advanced-pulse-tig-welding-part-1-2 Jack Thanks, Jack. I also found and read Part 2 of ...

A couple of thoughts: How long are your pre-gas and post-gas flows? Is your bottle nearly empty? When the bottle’s getting low, even though you think there’s plenty of pressure, sometimes you get contamination. I don’t fully understand it, but I believe I have encountered it. Have you had the proble...

I previously posted a topic on this subject, but the images seem to have disappeared, and I previously used a Hantek (Chinese) current clamp, which I lost all faith in. So I've decided to revisit and get fresh data. My welder is an R-Tech 210. R-Tech is a UK manufacturer/supplier. Although R-Tech de...

I just now watched that video, tweake. There is another video by Jody where he is doing some testing and I believe he is using a rotator and no filler. Kind of thinking he was testing various tungstens. I'll admit that I'm far from smart enough to drive this electronic stuff to "find" tha...

I just now watched that video, tweake. There is another video by Jody where he is doing some testing and I believe he is using a rotator and no filler. Kind of thinking he was testing various tungstens. I'll admit that I'm far from smart enough to drive this electronic stuff to "find" tha...

Here’s a link to that video I was referring to - I misremembered: he did use filler wire, sorry.

https://youtu.be/XzsfBV6_vNY

it seems to me that the higher the frequency, the more distinguished the feathers (secondary arcs) became. Jody had a video of that happening and he couldn't explain it. Well spotted. I think you are dead right. That’s why I included those shots of the aluminium strip; as the frequency increases, t...

Today, I had a look at the effect of ac frequency. I first tried with a hemispherical ball on the 2% lanth. 2.4mm electrode but I had a devil of a job trying to maintain the arc: the arc would start then sputter and pop. I checked and changed everything I could think of, and it was only when I tried...

wow thats some really nice pics 8-) :D :D :D :D Thanks, tweake, but it was your idea. There is one more thing I do want to try: take one particular tip angle, and look at the effect on the arc of changing the frequency, say, 50Hz, 120Hz and 200Hz. Ideally, I need to refine my setup so it’s more con...

Following tweake's suggestion, I had a look at some arc shots where I varied the tip angle on a 2.4mm 2% lanthanated tungsten on aluminium. 130 Amps, 70%EN, 100Hz The Lincoln Foundation TIG book recommends a hemispherical ball for 2.4mm lanthanated electrode, so I balled one up to that shape: 2.4mm ...

Oscar wrote: ↑Mon Sep 06, 2021 9:06 am the last set of tests are much more "proper", as things were much more consistent. Awesome 2nd round of testing!

Thanks, Oscar. “Practice makes perfect”, as they say.

sadly i don't have a proper tungsten grinder to compare to. i have dedicated diamond wheel to sharpen by hand. its ok but its still fairly variable. for me it has to be a fair way out to cause issues, but then again i'm not a good welder by any means. what would be really cool would be to compare d...

Today's photos. This time I decided to grind as obtuse an angle as I reasonably could , by hand, and to compare again ceriated with lanthanated at the same settings. Lanthanated tungsten: lanthanated 01.jpg lanthanated 02.jpg Ceriated tungsten ceriated 01.jpg ceriated 02.jpg I'm putting this to bed ...