Bob La Londe <none@none.com99> writes:

> On 3/28/2023 5:14 AM, Jim Wilkins wrote:
>> "Richard Smith"  wrote in message news:ly355pjniz.fsf@void.com...
>>
>> David Billington <djb@invalid.com> writes:
>>
>>> ...
>>> ... . I have an oscilloscope but have never connected it up when
>>> using the rectifier so don't know how well the rectifier smoothed
>>> things, maybe one day.
>>
>> Interesting to investigate, but the good question is always "does it
>> weld well?"
>>
>> ---------------------
>>
>> Recording while welding tends to require an expensive datalogger
>> that doesn't have other hobby uses. My cheap and simple DVM version
>> can't measure voltage and current fast enough or at the same time,
>> and my digital scope won't sample long enough. These require
>> additional user-designed circuitry to isolate and condition the
>> voltage and current signals.
>> https://www.dataq.com/products/di-1100/
>>
>
> Years ago I used to use a relatively cheap DVOM with a serial port
> output to prove to customers their power was "unclean." I'd just hook
> it to the circuit, tie the serial port to a laptop computer with a
> serial communications terminal program running, and leave it
> overnight. 12-16 hrs was no big deal on my old laptop computers.
> Sample time and serial port speed is of course an issue as you
> indicated, but I don't see why the same thing couldn't be done with a
> scope that has a data output. I'll have to go look to see if my cheap
> 2 channel digital scope has a communication port. (I've only ever
> used it for tuning servo drives).
>
> Upon a moments thought I recall that there are scopes with little more
> than an interface that use a computer for the display and
> computational capability. I am sure you could do data logging with
> something like that. When last I looked those units were even cheaper
> than my import 2 channel scope.
>
> I am aware that you used the word "Fluke." I understand that it might
> be beneath notice to consider a "cheap" tool, but there are ways to
> get most jobs done. I've never owned a Fluke meter.
>
> P.S. Upon another moments thought I recall I actually bought that 2
> channel scope (4 channels would have been ideal, but was out of my
> budget) to develop an idea I had for a medical heart monitor and
> training device. I did not work on it full time, and sadly Hewlett
> Packard came out with something a year or so later that performed a
> nearly identical function. I guess as soon as I had the idea I should
> have written it up and applied for at least a provisional patent. I
> still have boxes of electronic components on the shelf (some unopened)
> left over from that project idea. Its just that the only thing I
> actually used the scope for was tuning servo drives.
>
> --
> Bob La Londe
> Proffessional Hack, Hobbyist, Wannabe, Shade Tree, Button Pushing, Not
> a real machinist
>
>
> --
> This email has been checked for viruses by AVG antivirus software.
> www.avg.com

12 years ago
http://weldsmith.co.uk/dropbox/cranu/160128_datalog_AMV4000F/160128_datalog_AMV4000F.html
"Datalogging using a weld-monitor"

The devices have obviously come along since then

"Jim Wilkins" <muratlanne@gmail.com> writes:

> "Richard Smith" wrote in message news:lysfdr5dy1.fsf@void.com...
>
> 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?
>
> -------------------------
>
> 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.
>
> https://www.powerstream.com/dcdc-extreme-2412.htm
> "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.
> -jsw

I got in touch with Kuranda in Whaley Bridge.

Got Brett. Engaged. But message - no way.
He said you'd need a battery about the size of what's used in a
milk-float
https://en.wikipedia.org/wiki/Milk_float
to do anything.
He knew his welding. Feel of authenticity about his judgment.
He said Amp-hours look to only about 25% of rated for lead-acid.
He said Lithium you could look to 100% of rated.
Costs - he said getting to around GBP10000 (not far off US$).
When he realised I know the power in kW and the like, he ran with the
detail and said even for doing test welds which would be typically
less than a foot long, cost and size --- well it would defeat the
point (cheap and small).

He said lead-acid only works because maybe couple of seconds of
cranking an engine, max.
Chortling about starting diesels on a frosty morning by getting the
LPG-fueled forklift to tow you and you drop the clutch and crank the
engine that way until it fires.
Had a laugh, but as i said, he says no way will idea work of couple of
car batteries...

"Richard Smith" wrote in message news:ly355ogf7a.fsf@void.com...

Had a laugh, but as i said, he says no way will idea work of couple of
car batteries...

--------------------

I didn't want to tell you that, instead I hinted at it and looked for
relatively simple and inexpensive ways to get around the issues, like a 400A
alternator and adjustable voltage regulator. Even with it the vehicle
batteries won't stabilize and filter the voltage at 26V because their
internal impedance is too high when nearly fully charged. They might absorb
35A but not 350A.

A good welder might be able to repair a 400A alternator with a cracked
mount, well enough to run from a riding mower engine. I expect your time is
more valuable welding than tinkering, but a smaller version is on my list to
consider if I stumble onto the parts. Two days before you posted it I had
stopped at a heavy construction equipment electrical shop that might have
had a used alternator and ideas on adapting it, not that a used part in the
USA does you any good. He's provided me other things to modify or solve
problems, like fixing my truck's starter with a $20 brush assembly instead
of replacing it, and the carbons to make new Variac brushes.

In Army electrical school I heard a story about someone in Vietnam
improvising a stabilized high current power supply from a Jeep alternator
and a string of NiCads, which give 1.2V step resolution. In hot, steamy New
Guinea my father's Ordnance company improvised a beer cooler using part of a
Jeep engine for the compressor. A native made drinking glasses from beer
bottles by heating a ring of the glass in the center hole of a hot wheel
hub, then quenching the bottles to crack them along the hot line. Another
fire melted and smoothed the break. Their General Kenney was an inventor
himself and encouraged innovation.
http://pwencycl.kgbudge.com/P/a/Parafrag_Bombs.htm
The high ground water level in areas flat enough for airfields prevented the
Japanese from digging storage bunkers so they had to store everything on the
surface. Planes locally rigged with up to a dozen machine guns preceded the
bombers to suppress AA fire. The Jap military had neglected to properly
develop radar and they were easily surprised by treetop-level attacks.
Kenney also personally developed techniques for low level "skip" bombing
across the water and into the sides of ships, and the use of
altitude-sensitive photoflash fuses to make bombs dropped from high altitude
explode just above the ground. Unlike the Dambusters they used standard
bombs and fuzes, as cargo ships are much softer targets.

I got work by showing I could solve problems, not by laughing at them,
unless the inventor was too disconnected from reality. Even then I helped
with an E-Cat (cold fusion) until I could lead him to convince himself it
was a scam.

I know you can buy special purpose data loggers, I designed and built a
custom one myself, with adequate government funding. The projects I built
with proper new components and to industrial standards tended to cost
upwards of $50,000. My home versions cost maybe 1% of that, for example I
paid $22 used for a 1 Ohm 1KW variable resistor that is $1500 new, and $20
for an instrument that was originally $4000. It can measure the resistance
of 1 inch of welding cable.

"Richard Smith" wrote in message news:ly355ogf7a.fsf@void.com...

I got in touch with Kuranda in Whaley Bridge.

Got Brett. Engaged. But message - no way.
He said you'd need a battery about the size of what's used in a
milk-float
https://en.wikipedia.org/wiki/Milk_float

{{{ Here a typical hobby source is forklift or golf cart batteries that are
too far gone to last all day. }}}

He knew his welding. Feel of authenticity about his judgment.
He said Amp-hours look to only about 25% of rated for lead-acid.
He said Lithium you could look to 100% of rated.

{{{ But Li lacks the high current capacity. Marine dual-purpose lead-acid
batteries are a possible compromise. }}}

Costs - he said getting to around GBP10000 (not far off US$).

{{{ The inverter welder I looked at as comparable cost $9,000+. }}}

When he realised I know the power in kW and the like, he ran with the
detail and said even for doing test welds which would be typically
less than a foot long, cost and size --- well it would defeat the
point (cheap and small).

He said lead-acid only works because maybe couple of seconds of
cranking an engine, max.

{{{ When I was doing automotive electrical engineering I heard 30 seconds.
Kettering's breakthrough was to make a 5HP electric motor much too small and
light to run continuously without overheating. Starters depend on thermal
mass and low duty cycle and don't even have cooling fans. }}}

Chortling about starting diesels on a frosty morning by getting the
LPG-fueled forklift to tow you and you drop the clutch and crank the
engine that way until it fires.

{{{ I've started a VW with a dead battery by putting it in 4th, jacking up a
rear wheel and turning it by hand, then diving in to knock it out of gear as
it lugged at very low speed. I'd tried to coast-start it but reached the
bottom of the slope. }}}

Had a laugh, but as i said, he says no way will idea work of couple of
car batteries...

{{{ The idea wasn't dumb, it works for less demanding welding conditions.
Some things don't scale up well, see how long it took to match Brunel's
Great Eastern. }}}

"Jim Wilkins" <muratlanne@gmail.com> writes:

> "Richard Smith" wrote in message news:ly355ogf7a.fsf@void.com...
>
> I got in touch with Kuranda in Whaley Bridge.
>
> Got Brett. Engaged. But message - no way.
> He said you'd need a battery about the size of what's used in a
> milk-float
> https://en.wikipedia.org/wiki/Milk_float
>
> {{{ Here a typical hobby source is forklift or golf cart batteries
> that are too far gone to last all day. }}}
>
> ...

Thanks for being indulgent.
I simply have no idea of this.

I was lead astray because someone quoted as if fact that welders can
use a couple of car batteries to weld with gasless FCAW.
That cannot be?
I was "taken in" by that.

Anyway, all is learning.

On Wed, 29 Mar 2023 21:01:54 +0100
Richard Smith <null@void.com> wrote:

<snip>
>I was lead astray because someone quoted as if fact that welders can
>use a couple of car batteries to weld with gasless FCAW.
>That cannot be?
>I was "taken in" by that.

It's real... but maybe not for how you intended to use it. A few
comments in this video worth reading too. See:

READY WELDER: a long-term review
by Chris DesertDog

https://www.youtube.com/watch?v=JadODOJUPQ0

--
Leon Fisk
Grand Rapids MI

"Richard Smith" wrote in message news:ly7cuz72dp.fsf@void.com...

Anyway, all is learning.

--------------------------

It is, and innovation is exploring unknown territory. I call backing out of
dead ends the "Re" inherent to Research. If we took "Impossible" too
seriously we wouldn't have space flight, and maybe metal tools.