Might be an idea: Push button amperage control

Issue:
The potentiometers i have seen so far on TIG finger controls are bulky and fragile.
It adds additional weight and volume to the torch and cable. Sustaining ANY static weight during welding is tiring.

I really would like to see something like a push-button up/down control. That can be realized really small. Like a left-right momentary rocker switch, where pressing right side turns amperage up and left side vise versa.
Pressing the center of the rocker activates both switches and starts the arc. I was looking into that Intersil X9313 chip that does pretty much all of that.
The additional benefit: It might be possible to use very light-weight headphone-style cable between torch and machine.

Knowing my work-load, I will never get that idea realized myself. \\

Well- just an idea.

That is basically what 2T 4T switch control can do...set in 4T.

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Originally Posted by performance

That is basically what 2T 4T switch control can do...set in 4T.

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No, it is not. In 4T, you pre-set upslope/downslope etcetera. Every parameter adjustment for 4T is made at the machine.
Pressing the button once triggers start of welding, pressing a second time triggers end. That is 4T.

I mean a FINGER CONTROL that allows for a left-right-center push button style control of the amperage DURING WELDING.
I refer to a new FEATURE I WOULD LIKE TO SEE. Not a 2T vs. 4T.

While i have not seen a touch panel up and down finger control (and think it's a good idea), what i can suggest until the feature arrives is that you shop around for a new finger control.
The finger controls i have used in the past were set and forget. Meaning, the little wheel you swipe with your finger stays put when you let go of the wheel, so i didn't have to sit there and hold the wheel while i was welding, i only ever had to touch it to adjust amperage and start and stop the arc.
I can see where a finger control you have to constantly hold and fiddle with would get very old very quickly... i see lots of hand cramping and frustrating weld puddle control down that path.

I love my foot pedal control, tho. It just never felt natural to me to use a finger control unit.

I haven't seen anything on the market like that. I think it would be simpler to use a slider or a rotary knob. I favor more simple forms of operation. The more complicated it is, the less reliable it becomes.

I'm digging the OP's idea a lot. It's a good idea if you can figure out a way to allow it to communicate with the welder. You could even have an adjustable rate of increase/decrease in amps per second or maybe something like 5 amps each time the switch is closed.

if you really wanted to, you could rig up some kind of geared motor to adjust the pot in the foot pedal. the switch would just have to turn a motor on and off in either direction.

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Originally Posted by kenwhite

I was actually thinking of using an op-amp integrator circuit for the applied DCV - small package and cheap...

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How soon can you test ? :D

Ken, I definitely agree that would be the best way to go about it. I was just thinking outside the box in a simple way. :) On another note, I wonder if using a pressure sensitive switch would be practical so the harder you push, the faster the amperage will increase or decrease.

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Originally Posted by kenwhite

I was actually thinking of using an op-amp integrator circuit for the applied DCV - small package and cheap...

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That's a pretty good idea (the up and down buttons for ramping). I never cared for the idea of having to twist a pot on the torch.

If you do that, I'd suggest the OP97 from analog devices. It has very good bias current performance, especially over temperature. It's actually a bipolar device that's compensated, rather than FET input, so it doesn't have the nasty doubling every 10 degree behavior. They aren't that expensive either. I've used them for sample and hold circuits, which is essentially what you'd have, an integrating sample and hold.

Throw down some JFETs to switch the +/- charge pumps, and you'll be set!

I was thinking something like the pressure sensitive buttons that the play station 2 controller used.(the square,triangle, ect buttons) It would still use a up and down button, but the rate at which the curring setting would increase or decrease would depend on how hard you pressed the button. If you pressed down hard, the current would increase/decrease quickly while if you lightly squeezed it, it would slowly go up/down.