Hello everyone, a couple of months ago I started playing with the idea of building a tig pulser for my tig machine, something to go inline with the pedal.
Well, I sent a picture a month ago or so and now I have the semi-final version that works!
I will eventually start putting together some docs on how to replicate this BUT, I have concerns about trying to replicate something electronically while not understanding it so, for now, let me give you a high level overview, if someone is working on one or needs help, I am here.
The goal was to intercept my pedal signal and pulse it, my Everlast uses a 0-5V signal so, as long as you provide a 0-5V input into the machine, the amperage will follow. Note that:
0V = full power
5V = no power
The hardware that I choose is overkill but there is nothing really cheaper unless you start buying copies from China (totally doable just didn’t wanted to wait weeks for shipping)
I have used:
- Adafruit QtPy 2040 - it’s a dual core powerhouse but most importantly, it works with 5V inputs
- DAC/ADC - to convert digital signals to analog ones and viceversa
- Display - To show what is going on
- Rotary Encoder - To select the various options
- 7pin male-female connectors - same as my Everlast welder
Total of about ~$100 if you consider the breadboards, connectors, etc - It could be done much cheaper
Next step would be to 3D print an enclosure but maybe not, depending on how the test run will go, for now it seems to work fine.
Note: Turns out my welder doesn’t put out enough juice to power this little trinket, I can power everything except the display that seems it’s missing a few milliamps to be workable - so, for the time being I am powering this via a power bank while it’s connected to the machine
Super cool!! This sort of thing will be really valuable for a lot of folks. Feel free to reach out if you have any electrical questions, I was an electrical engineer in my past life.
My #1 problem is that the display doesn’t get enough power out of my welder so it doesn’t turn on (or better the led does but the display stays black) I have tried going low power but no cigar.
Without the display it works as intended but with the display connected I have to supplement the power via usb. I think I will replace that display with a 9-segment one - going old school!
Man, this is such a cool idea! I have an everlast that already has a pulser, so It’s not really useful for me. But, you now have my brain-gears turning about making a torch controller.
I’ve used these in the past for welding aluminum at a shop I used to work at (they were large parts, and we were moving around constantly, so a foot-pedal was not the best choice). But, they really suck ergonomically. (and that price!) I would constantly end up shoving the tungsten into the puddle while trying to adjust the amperage.
There’s other styles out there, sliders, trigger-pull, etc. But they’re all more or less that same price range.
For just basic dumb amperage control (no pulse control) all you need is a NO switch and a 1k potentiometer. (for the Miller 14-pin, at least. That’s primarily what I deal with at work). I’d have to poke around the pins on my Everlast pedal to see if it’s the same or similar.
Sounds like a fun 3D printing / tinkering project to come up with my own design. Would be stupid cheap also!
(Edit for future me, the Everlast pedal is a NO switch and a 10k potentiometer)
Just a thought - the 5V line from the welder going to the pedal might be signal only, i.e. not meant to drive electronics and thus could simply be the output from a uC in the welder. Pulling too many mA from a chip might damage it. (External power would be safer if unsure about the current supply situation on the welders side)
You are 100% correct sir.
Planning to use an independent 5v supply
First serious testing, 0.5s pulsing
I set the machine at 100A and had a 50%power and 10% low.