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Adding pulse functionality to a TIG welder

Posted: Sat May 23, 2015 1:13 pm
by Jattus
Hey guys,
I have been reading around on the forums for a while and finally decided it was time to make a post. (hopefully in the right section! haha)
My wife and I are designing/building devices that add pulsing functionality to TIG welder machines (welders that don't come with pulse functionality, such as the Miller Diversion 165 and 180).
I would greatly appreciate any feedback/advice/criticism that you guys have.
I'm hoping to be able to make these for people for a variety of different welders, and make sure it has all of the required functionality that people want. It has also been a fun project so far! And to put this out there, I am an engineer and am not the greatest welder... I'm still learning.
Here is what I am hoping to get some discussion going on about:
1. What are your thoughts on the settings/features that I have that are currently adjustable? (listed below) Is there anything that I am missing, or something that you would like to see?
2. What other welders are you guys using that I can build these devices for? Any inverter style TIG welder with an auxiliary input (pedal for example) should do.
3. What do you think of my project so far?
Thanks guys!

Specs:
* Square, Triangle, Sawtooth wave forms
* Pulse frequency is adjustable between 0.5 HZ and 50 HZ (1 pulse every 2 seconds to 50 pulses per second)
* Duty cycle and background amperage are both adjustable between 5% and 95%
* I have a delay before pulse start setting (gives time to get arc started before pulsing starts)
* 3 configurable profiles
* When device is turned off, welder reverts back to normal operation

Photos:
Image
Image

EDIT:
And here is a youtube video in case you are wondering how this puppy works!
GtWwz9YVqho

Re: Adding pulse functionality to a TIG welder

Posted: Sat May 23, 2015 5:54 pm
by nathan
How much? I'm not a serious buyer at the moment, but I am interested in knowing about these types of things, as I hope to one day be a serious buyer. Is this similar to the Lincoln pulse pendants? Also, is that foot pedal connected with an Ethernet cable?

Re: Adding pulse functionality to a TIG welder

Posted: Sat May 23, 2015 6:57 pm
by Jattus
nathan wrote:How much? I'm not a serious buyer at the moment, but I am interested in knowing about these types of things, as I hope to one day be a serious buyer. Is this similar to the Lincoln pulse pendants? Also, is that foot pedal connected with an Ethernet cable?
Hi Nathan,
I had never heard of the pulse pendants before so started googling it... I couldn't find much info on them, but it looks like it could be a similar idea.
I'm trying to price these things around $350 bucks. I'm hoping that is affordable enough to anyone wanting to upgrade their welder, and should be significantly cheaper than buying a welder with pulse functionality built into it.
Those pulse pendants look pretty expensive considering people are selling used ones for 500 bucks! haha

And to answer your other question, yes miller uses a RJ45 cable for the foot pedal control on the diversion, here is a picture for reference:
Image
At first I questioned millers idea for using that connector for a foot pedal cable, but it turned out to be a legit and reliable connector, plus the RJ45 cable technology is tried and true.

I can adapt the TIG Perfect box to any connector and any control voltage really.

Re: Adding pulse functionality to a TIG welder

Posted: Sat May 23, 2015 8:49 pm
by lwhaples
Interesting project.I just picked up a 180 Deversion to learn tig with so your box is of interest. Will be looking for any and all info on this.

Re: Adding pulse functionality to a TIG welder

Posted: Sat May 23, 2015 9:33 pm
by Jattus
lwhaples wrote:Interesting project.I just picked up a 180 Deversion to learn tig with so your box is of interest. Will be looking for any and all info on this.
Cool! How do you like it so far? I went ahead and added a youtube video we made so you can get a better idea of how it works. We only really demonstrated a project cleanup scenario, but hopefully you get the idea of its capabilities so far. I'm definitely open to some suggestions as well.
Here is the URL: https://www.youtube.com/watch?v=GtWwz9YVqho

Re: Adding pulse functionality to a TIG welder

Posted: Sun May 24, 2015 7:45 am
by lwhaples
Enjoyed the video. Really looks like a useful product.Like the idea of adding pulse to my welder.

Re: Adding pulse functionality to a TIG welder

Posted: Sun May 24, 2015 12:43 pm
by rick9345
Interesting upgrade.
Is the clicking/pulse sound in video as loud in the shop as on the video?

Re: Adding pulse functionality to a TIG welder

Posted: Sun May 24, 2015 1:43 pm
by Jattus
rick9345 wrote:Interesting upgrade.
Is the clicking/pulse sound in video as loud in the shop as on the video?
Haha no... we had the microphone too close to the welder and it was picking up some interference. Its actually not that loud. It sounds more similar to this as an example... (fast forward to 4:40) https://www.youtube.com/watch?t=321&v=z9jOFWpjRdU

Re: Adding pulse functionality to a TIG welder

Posted: Mon May 25, 2015 5:17 pm
by Wobulate
Jattus,

Are you creating an arbitrary waveform generator? It has been on the commercial market for about 30 years. Is your modulation occurring before the high current output generator?

I have researched many welders for this feature, some with pulse frequency of 0.1 to 20 Hz, others from 1.0 to 2,000 Hz. I am not sure why anyone would want a Pulse Repetition Interval (PRI) of 500 microseconds, it seems that this is approaching a constant DC level. The amount of cooling would be minimal.

Tell us more, how is this feature implemented?
Wobulate

Re: Adding pulse functionality to a TIG welder

Posted: Mon May 25, 2015 7:47 pm
by TRACKRANGER
Wobulate wrote:Jattus,

Are you creating an arbitrary waveform generator? It has been on the commercial market for about 30 years. Is your modulation occurring before the high current output generator?
...
Tell us more, how is this feature implemented?
Wobulate
The modulation must occur at control level, surely.

Jattus will respond accordingly, but from what I read, it's implemented by essentially controlling/overriding the foot pedal. It appears to connect in series with the pedal.

Frankly, I think it's a very smart unit, with waveform displays and digital read-outs that give an accurate indication of the settings and how they affect the weld current. I hope it's a successful add-on for those who don't have these features in their existing machines.

Trev

Re: Adding pulse functionality to a TIG welder

Posted: Tue May 26, 2015 8:03 am
by Jattus
Yep you are correct TrackRanger. And Wobulate, this device works with the low power circuitry (which indirectly controls the high power circuit). The high power output in the TIG welder is converted using rectifiers/transistors/solid-state switches, and these are controlled by a low power micro controller (basically a simple computer, it generates an output based on pedal input, and settings input on machine). The max pulse speed is directly related to the processor speed of the micro controller, which even the bottom line low end ones are still 5-20Mhz, which is more than capable of switching at very high frequencies. They just aren't built with a pulsing interface built into it to keep the machine cost down, while the more expensive machines have this interface. This is where my device comes into place

Re: Adding pulse functionality to a TIG welder

Posted: Tue May 26, 2015 8:46 am
by Jattus
So I had another idea along with increasing the frequency... I was wondering if I could add a 2nd frequency setting on the display (e.g. "Hz 2") and this would basically add a second frequency only on the peaks of the generated wave. Here is an example illustrating this:
Image

"A" Is how the wave typically looks, and "B" is with this 2nd high frequency (this would also work on the triangle and sawtooth wave forms). I was thinking that the benefit to this is that you can still get that tight arc, along with a slower pulse as well. Basically the best of both worlds. The only problem I see with it is the total duty cycle would be reduced significantly, and you would have to increase amperage to compensate... though this might not be a big deal. And I am running out of real-estate on the screen! haha. I could probably get away with 1 more setting and still have the graph decently visible.

Re: Adding pulse functionality to a TIG welder

Posted: Tue May 26, 2015 8:54 am
by TRACKRANGER
Jattus

Keep up the great work. I really hope you establish a successful sales avenue. Your challenge is with so many different machines in the market, your device needs to be very flexible to accommodate a wide range of products.

I wonder if Jody would be interested in reviewing?

Trev

Re: Adding pulse functionality to a TIG welder

Posted: Tue May 26, 2015 12:02 pm
by LtBadd
Jattus wrote:
nathan wrote: Also, is that foot pedal connected with an Ethernet cable?
Hi Nathan,
And to answer your other question, yes miller uses a RJ45 cable for the foot pedal control on the diversion, here is a picture for reference:
At first I questioned millers idea for using that connector for a foot pedal cable, but it turned out to be a legit and reliable connector, plus the RJ45 cable technology is tried and true.
I can't imagine a RJ45 connector standing up to the kind of use a foot pedal typically gets in a weld/fabrication shop

Re: Adding pulse functionality to a TIG welder

Posted: Tue May 26, 2015 1:59 pm
by soutthpaw
Jattus wrote:
nathan wrote:How much? I'm not a serious buyer at the moment, but I am interested in knowing about these types of things, as I hope to one day be a serious buyer. Is this similar to the Lincoln pulse pendants? Also, is that foot pedal connected with an Ethernet cable?
Hi Nathan,
I had never heard of the pulse pendants before so started googling it... I couldn't find much info on them, but it looks like it could be a similar idea.
I'm trying to price these things around $350 bucks. I'm hoping that is affordable enough to anyone wanting to upgrade their welder, and should be significantly cheaper than buying a welder with pulse functionality built into it.
Those pulse pendants look pretty expensive considering people are selling used ones for 500 bucks! haha

And to answer your other question, yes miller uses a RJ45 cable for the foot pedal control on the diversion, here is a picture for reference:
Image
At first I questioned millers idea for using that connector for a foot pedal cable, but it turned out to be a legit and reliable connector, plus the RJ45 cable technology is tried and true.

I can adapt the TIG Perfect box to any connector and any control voltage really.
Powcon used to build them for their machines, I used to have one that I got almost free but never got around to setting it up.

Re: Adding pulse functionality to a TIG welder

Posted: Tue May 26, 2015 3:40 pm
by Oscar
Wobulate wrote:Jattus,

Are you creating an arbitrary waveform generator? It has been on the commercial market for about 30 years. Is your modulation occurring before the high current output generator?

I have researched many welders for this feature, some with pulse frequency of 0.1 to 20 Hz, others from 1.0 to 2,000 Hz. I am not sure why anyone would want a Pulse Repetition Interval (PRI) of 500 microseconds, it seems that this is approaching a constant DC level. The amount of cooling would be minimal.

Tell us more, how is this feature implemented?
Wobulate
Pulsing is independent of duty cycle. if the duty cycle is 10% for the high peak, and the other 90% is spent on the base current, even 2000 PPS would reduce heat input. Not saying it would be useful, just saying.

Re: Adding pulse functionality to a TIG welder

Posted: Tue May 26, 2015 5:14 pm
by soutthpaw
Jattus wrote:So I had another idea along with increasing the frequency... I was wondering if I could add a 2nd frequency setting on the display (e.g. "Hz 2") and this would basically add a second frequency only on the peaks of the generated wave. Here is an example illustrating this:
Image

"A" Is how the wave typically looks, and "B" is with this 2nd high frequency (this would also work on the triangle and sawtooth wave forms). I was thinking that the benefit to this is that you can still get that tight arc, along with a slower pulse as well. Basically the best of both worlds. The only problem I see with it is the total duty cycle would be reduced significantly, and you would have to increase amperage to compensate... though this might not be a big deal. And I am running out of real-estate on the screen! haha. I could probably get away with 1 more setting and still have the graph decently visible.
Basically you are doing pulse on pulse that lincoln has on it's hi end migs like the 350mp. Or advanced pulse as found on the fancy Everlast machines.

Re: Adding pulse functionality to a TIG welder

Posted: Tue May 26, 2015 7:08 pm
by Otto Nobedder
I've seen similar in AC mode. I've welded .049 wall 6061T-6 3/8" instrument tube, and had the benefit of 400Hz and pulse, so I can vouch for the pulse-on-pulse idea.

I would suggest, as a product, having a stepped level of products, where one could simply buy the pulse-box you originally described, which easily equals the functions of a basic Xformer welder with pulse, or "for a few dollars more" buy the pulse-on-pulse version. Don't try to shove it all in one box and sell it, or you'll exclude some who don't need that much "feature".

Steve S

Re: Adding pulse functionality to a TIG welder

Posted: Sat May 30, 2015 1:25 am
by WJH
Basically, I see an 8$ micro processor spitting out a PWM signal to control the foot pedal input. Emulating pulsing with the foot pedal with precision.
Interesting idea, one could do this with an Arduino and a few extra parts.

Re: Adding pulse functionality to a TIG welder

Posted: Sat May 30, 2015 2:34 am
by TRACKRANGER
WJH wrote:Basically, I see an 8$ micro processor spitting out a PWM signal to control the foot pedal input. Emulating pulsing with the foot pedal with precision.
Interesting idea, one could do this with an Arduino and a few extra parts.
Hmmm. Do you think you're maybe over simplifying?

The $8 micro isn't going to do anything without a stack of additional components and lots of design. Yes, there are other micro's that could do it, but it also needs much more than that. Programming, power supply, housing, filtering, shielding, decent (color) display, operator input control, development, testing, design for compatibility with multiple disparate machines, marketing, packaging etc, etc.

Re: Adding pulse functionality to a TIG welder

Posted: Sat May 30, 2015 2:35 am
by weldin mike 27
I'd say a little more effort has been expanded than that. One couldn't just do it, I'm one, and I am just glad when the machine works, if not, I call the maintenance sparkies.

Re: Adding pulse functionality to a TIG welder

Posted: Sat May 30, 2015 6:16 am
by rake
WJH wrote:Basically, I see an 8$ micro processor spitting out a PWM signal to control the foot pedal input. Emulating pulsing with the foot pedal with precision.
Interesting idea, one could do this with an Arduino and a few extra parts.
Wow! Just drag the guy out back and kick him in the dick why don't ya?

Re: Adding pulse functionality to a TIG welder

Posted: Sat May 30, 2015 7:38 am
by TRACKRANGER
So far it seems the $8 micro really ain't going too far to actually deliver the goods

WJH, Welcome to the Forum. But you need to be realistic about statements for them to be received credibly.

Trev

Re: Adding pulse functionality to a TIG welder

Posted: Sat May 30, 2015 7:45 am
by lwhaples
I see it as a really cool product.Maybe cause I have a 180 Diversion. Looks to me as well thought out and user friendly.

Re: Adding pulse functionality to a TIG welder

Posted: Sat May 30, 2015 11:38 am
by soutthpaw
WJH wrote:Basically, I see an 8$ micro processor spitting out a PWM signal to control the foot pedal input. Emulating pulsing with the foot pedal with precision.
Interesting idea, one could do this with an Arduino and a few extra parts.
If it's so simple, why don't you make one yourself..... Yeah, that's what I thought. I'm sure the OP had thousands already invested in prototyping, I commend him for his creativity and American build and ingenuity.