Author Topic: Getting Max Amp limits on a Wave 200KD AC/DC TIG machine  (Read 761 times)

Offline Joco

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Getting Max Amp limits on a Wave 200KD AC/DC TIG machine
« on: May 26, 2019, 09:55:33 AM »
While this TIG machine is not a bad little unit one of its annoying limitations is how it treats a pedal. When a pedal is added on unless it is of the dual knob variety the pedal will always do 0 to Max (200) amps. What you really want is to be able to set the max Amps that can be dialed up with the pedal while having the pedal giving you increased resolution across the new amp range. This is something you want to be able to do when working on thin materials or when doing operations that are sensitive to heat variations, such as aluminium welding or TIG brazing with Silicon of Aluminium bronze.

So this is the rig I have. 200Amps, DC and AC capable and pulse. Its not silly expensive but is still reasonably capable for a home machine.


After some digging about with the pedal wiring I figured out the pedal plug has the following wiring:


So after a bit of pondering, net snooping and checking with Bruce I came up with this circuit:


So doing a hack check with a spare 10k pot I had about.


Finished "soap on a rope" control box.  The switch essentially enables/disables the pedal by allowing me to stop the internal pedal switch from activating.  So when in the "OFF" position I can push the pedal to max and adjust the peak amp setting that flooring the pedal will give without having the welding activate gas and the HF start.  As you can see I managed to rip a bit of plastic out when drilling the switch mounting hole.  One of those blistering four letter word moments. But a little superglue and its all sorted and perfectly serviceable.  If it ever breaks completely I think I will replace it with the aluminium version.



And the overall look.  :-)


Ultimately a very simple mod and for anyone with a Wave 200KD machine well worth the effort. You could probably do the same thing on any machine that has the maxamp limitation.

Cheers,
J
James
Wellington - NZ

Offline Muzzer

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Re: Getting Max Amp limits on a Wave 200KD AC/DC TIG machine
« Reply #1 on: May 26, 2019, 03:30:13 PM »
Yes, it's a bit odd that they chose to do it that way. My old Miller TIG machine has a big knob on the front panel that sets the max current and the pedal can not exceed whatever that setting is. I can run below 10A and over 300A, so this sort of control is essential. Sounds like a very sensible mod you've done there!

Offline bent

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Re: Getting Max Amp limits on a Wave 200KD AC/DC TIG machine
« Reply #2 on: May 28, 2019, 08:19:24 PM »
Joco,

I have an Everlast Tig machine with that problem too.  I'll have to pull out the wiring diagram again and see if that mod, or something like it, would work with mine.  Thanks for kicking the dust off my brain cells. :)

Offline Joco

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Re: Getting Max Amp limits on a Wave 200KD AC/DC TIG machine
« Reply #3 on: May 30, 2019, 01:09:28 AM »
Bent - if your pedal is using a linear POT then you should be able to make something work. If the POT is logarithmic then its going to get entertaining. 

J.
James
Wellington - NZ

Offline bent

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Re: Getting Max Amp limits on a Wave 200KD AC/DC TIG machine
« Reply #4 on: May 30, 2019, 05:46:20 PM »
I don't think its log, but will check when I start fiddling.  One more thing to do, adding a tank pressure gage for my Ar bottle is next.  Been too busy with son #4 and his school events.  After this summer, he'll be off to college along with #3 son, and I'll get some shop time in, I think.

Offline Muzzer

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Re: Getting Max Amp limits on a Wave 200KD AC/DC TIG machine
« Reply #5 on: May 30, 2019, 07:37:56 PM »
Log pots are only used on audio equipment due to the way our ears respond to sound levels. You won't find anything like that on a welder.

Offline Admiral_dk

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Re: Getting Max Amp limits on a Wave 200KD AC/DC TIG machine
« Reply #6 on: May 30, 2019, 10:12:30 PM »
Quote
Log pots are only used on audio equipment due to the way our ears respond to sound levels.

Not completely true, but it is admittedly very rare to see them used elsewhere ....