I was thinking how good if this solution gave the most stable smooth arc ever known. With being inherently DC... Yes if there was a regulator which maybe only has to throw away a bit of power through resistors but adjusts continuously according to a voltage sensor at the torch. Provided you "topped up" the voltage to just over the arc voltage. So that 26V is just less than what's available DC. However, that's not what you are saying with the "buck-boost". I'll need to study that suggestion.
!!! Kuranda UK Ltd Whaley Bridge is just the other side of the hill at the head of the valley here where I am in the Peak District / Derbyshire Dales.
Funny how things like that come to mind. I still recall my grandmother sending me down the drainage between the road and the various properties picking wild black berries for a pie. The ditch was a main drainage many others fed into. You might have seen me from the road if you were paying close attention, but none of the property owners knew I was shredding my forearms in blackberry brambles leaning from their property into the ditch.
I was thinking how good if this solution gave the most stable smooth arc ever known. With being inherently DC... Yes if there was a regulator which maybe only has to throw away a bit of power through resistors but adjusts continuously according to a voltage sensor at the torch. Provided you "topped up" the voltage to just over the arc voltage. So that 26V is just less than what's available DC. However, that's not what you are saying with the "buck-boost". I'll need to study that suggestion.
!!! Kuranda UK Ltd Whaley Bridge is just the other side of the hill at the head of the valley here where I am in the Peak District / Derbyshire Dales.
-------------------------- The output isn't inherently DC any more, but it can be filtered to approximate DC as well as you can afford.
Buck-boost converters don't need to lose power in resistors, they are the DC equivalent of a Variac. They convert incoming DC into pulsed AC and then rectify it back to DC. The pulse's width determines its energy content and the output voltage. It's a closed loop, active circuitry measures the output voltage and varies the pulse width to maintain the voltage at where you set it.
The operation is somewhat similar to a Hydraulic Ram, with energy oscillating between velocity (current) and pressure (voltage), as in a pendulum. The inductors L1 and L2 create the electrical equivalent of inertia, like a car ignition coil that produces high voltage when the points open.
It's difficult to explain in detail, what we call FM (freakin' magic) . See if this helps:
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I mentioned the buck-boost because it can operate with equal or only slightly higher or lower voltages in and out. There are other designs for switching power supplies that don't use series capacitors and may be better suited to your high current. This one should at least get you in the door and give you credibility. Knowing the words can help even if you don't know their meaning, they may assume you do.
I downloaded the manual and the "power" setting is a bit vague on what it does. Increasing/decreasing the pulse would change power. Whatever is going on was unique enough to get a patent approved for it.
Batteries recommended are two ODYSSEY 65-PC1750 which are "Odyssey Drycell Batteries - 12 V, Deep Cycle/Starting, 950 Cold Cranking Amps, Top Stud, Series 65"
My Millermatic 200 supposedly adjusts from 10-30 vdc in 2 volt increments. Rated at 60% duty cycle at 28vdc and 200 amps.
I noticed several links to videos but have not looked to see if they are anything interesting...
Are you saying that it would be impractical if not impossible with tens of thousands of mid range commercial fab shop machines that just have a handful of fixed stops for setting voltage instead of a continuous variable voltage control, because their control is not good enough to hit the perfect voltage?
For Ali-GMAW an adjustment of about 0.2V will make a perceptible difference.
0.2V range on about 25V
The entire usable range for steel vertical up FCAW was 0.6V, when I was in turkey in 2015 on the 3rd Bosphorus Bridge project. From those who chose to keep the heat "low" and weave-in the bead shape to those who chose to fill the fillet corner and leave it all to the flux/slag to control the bead shape.
So yes you could has "taps" in some sort of resistance arrangement to trim down a voltage, but it would need fine steps. Copper-and-iron GMAW machines have a "coarse" tap knob and a "fine" tap knob. The fine "splits the difference". It's hard to beat a *good* copper-and-iron machine. Yes its output will go up and down with the line voltage. And other variables. But on the other hand the machine with its taps going into the hard invariant wiring of the transformer gives a very stable repeatable outcome.
The hypothesised device - if you are not familiar with commercial welding with everything that you need in-order (you are the welder; you demand - and they know every other welder would do identically) - you need stable consistent voltage adjustment to much finer than
1/100th part.
I believe. From my experience. I tend to be out on my own on jobs. So it's your choice whether you find what I say credible or now.
Ahhh, now you explain you are selling me the idea.
So with a battery which at that current is maybe supplying 24V, I could boost up to 26V and very finely trim in the needed range from
24V to 26V...
Thanks for explaining. I'll go back to that link.
Mega thanks. Yes I should get over to Whaley Bridge. It's less than 1/2hr by car.
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The parts and labor may be at least as expensive as a line-powered inverter welder of the same output. The buck-boost converters I have for moving charge between batteries do what you ask in principle but at far lower current levels. Like birds they may not scale up very much larger.
Thank you. It is. I want you to understand I am NOT arguing with you or disputing you. I have plans and I want to perform better in the future than I did in the past. Your welding experience far out weighs my own. To the point where my experience is virtually zero by comparison. Sometimes when I say I have done something I may mean just once. All I can do is say what I think I know and hope you correct me with better knowledge and better experience. When I point out how my very limited experience has differed I am NOT arguing. I am seeking better knowledge.
I have always struggled (and sometimes succeeded) with MIG aluminum with my machine even though it was sold as a MIG aluminum machine. It came with two independent gas solenoids for two independent gas bottles, and two independent guns. One is a regular MIG stinger, and the other is a spool gun. You set the welder and pull the trigger on the gun you want to use. Switching from one to the other is as easy as setting one gun down and picking up the other. It has fixed taps for voltage, and I have found most of the time I can get a little better results by running recommended power settings and adjusting the wire speed. Usually faster than recommended. Its a low/mid class fab shop commercial welder. A Miller 212. It is not an industrial welder however.
I have pushed The Miller to its duty cycle, but only when I have had largish assemblies fully prepped and tacked. The pauses between welds were measured in the time it took my helmet to go light so I could reposition on the next joint. Seconds. Generally if I am in the groove and the welds start going bad I assume I am reaching the duty cycle limits. I guess this because with several different welders if I let them cool down for a little while either I am rested enough to weld better or the machine is cooled off enough to weld better. I deduce this because two of those are cheaper machines that have a very low duty cycle. I can see the weld getting worse before the thermal protector trips. If I push it the thermal protector trips shortly after. Anyway, the Miler is not a box store consumer machine. You can hit its duty cycle, but you have to be trying.
That's a nice welder, looked up the manual for it👍 My voltage switch only has 6 positions but I can swap a cable plug to High Range and get 6 more (12 total Voltage settings on Millermatic 200). Seems I recall some overlap in the settings though. It has a better duty cycle than yours but physically looks almost identical. Had a particular job in mind when I bought it and sized it big enough to get 100% duty cycle for the weld settings I wanted to run. And it did that just fine. A lot of times the fan wouldn't even come on while welding. Kinda nice not having to listen to a fan drone away...
Never got a spool gun for it though which was on my wish list. Had no particular need, but just-in-case.
Since picked up an old Solar, which is likely an old Century made buzz box. Nowadays it's much easier to drag that one out, pick a rod for the job and get it done ;-)
I haven't burned a stick in a few years, but if I do I'll probably use the AHP inverter (AC/DC Pulse Tig and Stick) machine for it. I don't ever want to dig the AC cracker box out from under the table again.
I think I've got it. The "boost" is the electrical equivalent of a hydraulic ram, as was earlier said.
Maybe a higher-current device is readily possible. Something with headroom to say 400A but actually aiming 180A to 250A.
with 2 car batteries it likely only has to boost
that boost is only something like 2V or 3V - not a big proportion of around 24V.
Maybe a much simpler device, but with big high-current components.
The other thing you could do is have three car batteries in series and only have to "buck". There you efficiently trade voltage for more current?
I should go to Whaley Bridge - that Co.
I had an electronics company actually come a long way to seek audience with me once. That company brought out a new electronic device with one key selling point being what they built in after seeing how I did what I did. I post-processed data I'd extracted from their device on a unix computer. Showing them the scripts, they recognised it, scribbled-down the math expressions represented by my scripts, and programmed that arithmetic operation into the embedded processor. That got true power of a Pulse welding machine. They helped me loaning the machine so I helped them with the improved next generation.
So hopefully these folk in Whaley Bridge will talk with me.
The other thing you could do is have three car batteries in series and only have to "buck". There you efficiently trade voltage for more current?
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That is a very good idea, you could have 24V from the standard truck electrical system with a high current alternator, and an isolated 24V to 12V converter to keep the third battery charged. The batteries could be allowed to droop while welding without affecting the 26V output as long as the alternator and converter can keep up with the duty cycle, which I think would have to be low to keep the cost down, otherwise there may be little or no advantage over a portable engine-powered welder.
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"These converters are fully isolated, so will work in positive ground or negative ground applications." ">1500 volts isolation from case to any terminal, >1500 Volts isolation input to output." So there shouldn't be a problem with connecting the negative side of the output to the positive side of the input, to boost 24V to 36V. That would be a short circuit if the output isn't isolated.
I haven't given up on the 24V 400A alternator with adjustable regulator but right now I'm busy doing my taxes and researching who to vote for tomorrow.
I've read/heard that some of those multi-process machines don't work so well burning DC rods. Especially 6010's. Speculation that it is inherent to the design/multi-process limitations... I'd probably still give it a try but wouldn't be surprised if it didn't go well.
My old buzz box is just AC. Runs really nice when you manage to get the amps for the rod and what you're working on set right ;-)
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