I've been putzing with a design for an add-on pulser for my Miller 180SD
TIG welder at work. After 3 years, on-and-off (mostly off), I've finally
got a working unit. I posted it under "TIG Pulser" on the Dropbox:
I finished it today, so I can't give you any long term use information.
But, it seems to work as designed.
Many thanks to Gary Campbell, Ray Sommer,....and especially Ernie
Leimkuhler for his willingness to share all his welding experience with us.
Wow professional looking front panel, good job! I like the way you
transition from Hz to seconds on the one dial, that makes sense.
Does it work well? I love the pulser on my invertig, almost makes my
welds look good :)
I've been wondering this also. Two per second, I think I understand:
Sets a fixed interval for the heat, fill, move cycle. 20 per second?
What is the benefit? That seems certainly faster than I can see.
Don Foreman wrote in
Rather than try to explain, I'll copy a portion of a posting from last
Saturday from Ernie Leimkuhler, that was a copy from him responding to
me when I asked exactly the same question a couple of years ago. :)
I'll get back to you later on the visit, as I've just finished it, and
this is the first time I've used a pulser.
And again thanks Ernie!
From past posts of mine [Ernie Leimkuhler]:
A pulser is a device used to interrupt a welding arc.
Mostly used on TIG, but can also be used for MIG.
The idea is to cycle the arc from high amperage to low amperage.
The metal melts at the high amperage and solidifies at the low amperage.
There are 3 settings for a pulser.
1. Background amperage
This sets the low amperage and is usually set as a percentage of the
So if you main amperage is 100 amps, and the Background Amperage is set
for 50%, then you Background Amperage is 50 amps.
2. Percentage of On time.
This sets how much of each pulse cycle is spent at the high amperage
and how much a the low level, once again by percentage.
A setting of 50% evenly splits the cycle between low and high amperages.
Less than 50% on On time gives a Spikier Pulse.
Greater than 50% gives a Softer Pulse.
3. Cycles per second.
This is the really confusing one, because it has the most profound
Older TIG pulsers only allow up to a maximum of 10, or less, Cycles Per
Second (Hertz - Hz), but the newer Inverter TIGs allow much higher
My Maxstar 200DX goes up to 200hz.
The lower pulse frequencies are for traditional pulser use, where you
run between 1 and 2 hz on the pulse. adding filler metal on every pulse
or every other pulse as you progress across the weld.
The higher frequencies have a much different effect, in that they tend
to make the metal super-liquid, allowing it to flow and wet out much
These higher settings work very well with autogenous welds where no
filler metal is added at all.
These are also called Fusion or Flow welds.
I also found these higher frequencies worked well for vertical welds in
heavy Silicon Bronze.
Now the reason for all this pulsing is rather simple.
Lets start with a piece of 16 ga steel.
At 0.062" thick the proper amperage would be 1 amp per 0.001" of
thickness or 62 amps, for a flat-butt weld, full penetration, single
You could easily TIG weld a seam in 16 ga Steel using a continuous 62
However a spike of high amperage will melt the metal much faster than a
low amperage, so you could weld faster at 80 amps than 62 amps, but at
that heat you risk overheating the metal and causing undue warpage or
burning of the steel, so you mix an interval of 80 amps with an
interval at 40 amps.
The low amperage interval allows the puddle to solidify back into steel,
without allowing the arc to break.
By pulsing the weld across the bead you get a very orderly row of
rings, that give that distinct stack-of-dimes look to the weld bead.
You adjust the exact pulse frequency to suit your style and speed of
welding as well as the thickness of the metal.
The other benefit is that over all, you have put less heat into the
metal, so you have less distortion.
A smaller, consistent weld bead is often stronger than a larger
inconsistent weld bead.
The more consistent a weld is the more the stresses apply along it's
Any peak or valley in a weld becomes a stress point for failure to
Whether you choose to add filler metal on every pulse, every other
pulse, every third pulse or not at all is dependent upon your own
welding style and the
circumstances of the weld.
Where pulsers become bewildering is when you start messing with the
percentage settings for the Background Amperage and percentage of On
The number of possible combinations is huge, and there is little or no
guidance given in the welding world as to application.
Pro-Fusion has an excellent series of webpages with online calculators
that allow you to punch in the overall required amperage you want and
how fast you want to weld and it will generate pulser settings for you.
It still gives no guidance as to when you want a Spike pulse, or a Soft
pulse, but it gives you something to play with.
50%, 50% and 1.4hz, is a setting that works for most sheet metal.
All I can say is that until somebody puts out some really authoritative
research showing what pulser settings are best for what combination of
weld and materiel, we will all be out there experimenting on our own.
I have searched for such a book for 5 years, and given up.
Hopefully some day soon the welding engineers will decide to enlighten
us lowly welders.
The guideline I can give you is that the thinner the materiel the more
it benefits from a spikier pulse.
I have yet to find a benefit to a really soft pulse.
An example of an extreme spike pulse is that you can weld a popcan at
as long as you set your pulser to 2% On Time and 2% background amps.
"Brent" wrote in
That's a rabbit that I'm not going to try and chase. Miller seems to
add new features as soon as you have purchased one of their machines. ;)
The pulser was not a necessity, but seemed like an interesting
project...with a potentiol practical outcome.
"runch" wrote in
Thanks. I was happy with the way it came out. The front panel was developed
in QuickCAD (formerly AutoSketch), and laser printed on transparency film.
I used 3M #77 advesive to attach it to the panel and trimmed it with an
Exacto knife. The photo made it look more like silk screened.
I'm just starting to use it. Never used one before, but so far it performs
as I would expect.
" firstname.lastname@example.org" wrote in
I've gotten so much valuable information from the people on this, and other
newsgroups, that I thought it was time to share a little of "my"
experience. Didn't feel there was a big enough market to try and sell this
as an after-market add-on, or as a kit. The circuit board was $59 for
three, from ExpressPCB. I still have two left, if anyone wants one for
$20. I also just realized today, that if I had cut the cord from the foot
control in two, I could have used any 5-pin connector pair on the box. Oh
well...I hope someone can make use of the posting. :)
I dont blame you for that one
I havnet used to pulser yet. I dont think my good old fashioned TIG
welding is up to snuff yet doing plain old welding so i'm not going to
get fancy till i can do plain and reliable
But out of curiosity what model and type of connector is that 14 pin
a finger amperage control for out of position work would be a nice
project in my books (though i prefer the pedal) and the only part that
i havent stumbled across (Or thats sitting in my electronics parts
pile) is that Amphenol connector.
I know Amphenol makes them but i havent found it (too big a forest of
products they make to find the 14 pin welding connector tree)
But Great work on the pulser unit
Ken Moffett wrote:
That got my attention! This project just went on my "to do" list. I
probably have all the parts on hand, except maybe for the pots. Ax
Man has pots.
I'd be interested in one of your PCB's if you still have any left.
Most folks would do this with a PIC processor, but your linear design
is clean, straightforward and very un-fussy. Probably also pretty
EMI-proof, and no higher chipcount than a UP would need.
What is that block in the lower righthand corner of the schematic,
"Brent" wrote in news:1163686746.277546.264250
The connectors are listed in my TIG Pulser.txt file in thre Dropbox.
The AMP/Tyco Connectors are available from Electronic Industries Inc.
P.O. Box 266
Oshkosh WI 54903-0266
1 each: AP-213571-2?Plug
1 each: AP213570-1?Receptacle
1 each: AP206070-1?Plug Shell w/Cable Clamp
10 each: AP-213603-2?Pin, 18-14, Tin,
10 each: AP-66601-2?Socket, 18-14, Gold
Total (w/ shipping) $27.82
There's no magic in these connectors. They only used 5 pins. As I said
in another reply, if I had thought about it I could have cut the foot
control cable near the machine end and inserted any 5-pin connector pair
I wanted. Then use that as the connecting point for the pulser. Even
without the pulser you could do that for your finger control. Were you
looking at the finger control ("tig remote.xxx") files posted in the
Dropbox? Looks pretty good.
Don Foreman wrote in
I still have the PCB's. The Log-taper pot was the only one I had to buy.
I had been through Axman's stock with no luck. ;) I'll look through my
old PO's and get you the vendor and part #.
I had thought about a PIC halfway through the developement. But the HF
arc starter was blowing out the LM324 on one of my perf-board
prototypes, and I didn't want to get into that noise screwing up program
steps. The addition of a ground plane on a PCB and the ferrites and
bypass caps on the wires entering the box solved that. So, that may be
the way to go now. Though the analog verson did everything I wanted.
The block is a DC-DC converter, to get a bipolar supply (+/-12vdc) for
the op-amp, from the +20volts in the welder. It needed that to drive
the P-channel MOSFET into full conduction. It was a 12vdc input DC-DC
converter that I already had...that's why I had to put U1 in there...to
get the 20v down to 12v. I can't find one with a 12v input that has the
same footprint and pinout to directly drop in. That's one of the mod's
on the "Mark II" if I ever did another one. ;)