welder idle control?
Grant Erwin
to energize an electromagnet-type (pull) solenoid mounted on the carburetor
which pulls the governor arm to the idle position, and to sense when there
is weld current, in which case it deenergizes the idle solenoid. The idle
solenoid still works. The bad part is obsolete and unobtainable.
I'm wondering if there isn't a way I could rig a remote switch to turn on
or off that solenoid by hand. It would be a pain, but better than having
no idle control at all.
Ideas?
Grant Erwin
--
Posted via a free Usenet account from http://www.teranews.com
JR North
it and repair the problem (bad caps, prolly). If it's an IC, fergetit.
JR
Dweller in the cellar
Grant Erwin wrote:
--
--------------------------------------------------------------
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If you're not the lead dog, the view never changes
Doubt yourself, and the real world will eat you alive
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No skeletons in the closet; just decomposing corpses
--------------------------------------------------------------
Dependence is Vulnerability:
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"Open the Pod Bay Doors please, Hal"
"I'm sorry, Dave, I'm afraid I can't do that.."
BobH
> I have an old Miller welder with a bad idle control module. It's supposed
> to energize an electromagnet-type (pull) solenoid mounted on the carburetor
> which pulls the governor arm to the idle position, and to sense when there
> is weld current, in which case it deenergizes the idle solenoid. The idle
> solenoid still works. The bad part is obsolete and unobtainable.
>
> I'm wondering if there isn't a way I could rig a remote switch to turn on
> or off that solenoid by hand. It would be a pain, but better than having
> no idle control at all.
Is the obsolete/unobtainable part a complete board or is it a specific
part on the board? If it is a complete board, is there any information
available on the board like maybe a schematic? Also, is the board
accesible or is it potted in epoxy or something similar?
I would not expect that module to be horribly complicated and if you can
get to the components, it should be fixable. Lack of docs would make it
harder, but probably not impossible. Also, there are shops that sell
idle control modules. These guys advertise some: http://www.weldtron.com
BobH
ramray
or others what were the parameters that triggered the solenoid, and try to
replicate the circuit using modern components. what is the solenoid coil
operating voltage. What model welder is it. It does not appear to be a
very complex circuit. I would hate to have to manually throw a switch every
time you stopped welding. Sorry I cannot be any more help, not knowing the
details. See what the others in the group have to say.
Best Regards,
Ray R
"Grant Erwin" <gr...@NOSPAMkirkland.net> wrote in message
news:4754c163$0$25979$8826...@free.teranews.com...
Ernie Leimkuhler
Grant Erwin <gr...@NOSPAMkirkland.net> wrote:
> I have an old Miller welder with a bad idle control module. It's supposed
> to energize an electromagnet-type (pull) solenoid mounted on the carburetor
> which pulls the governor arm to the idle position, and to sense when there
> is weld current, in which case it deenergizes the idle solenoid. The idle
> solenoid still works. The bad part is obsolete and unobtainable.
>
> I'm wondering if there isn't a way I could rig a remote switch to turn on
> or off that solenoid by hand. It would be a pain, but better than having
> no idle control at all.
>
> Ideas?
>
> Grant Erwin
Precision Welder Repair has a shop in Portland they send broken obsolete
boards to for component level repairs.
We had some boards from South Seattle repaired there.
Steve W.
> I have an old Miller welder with a bad idle control module. It's supposed
> to energize an electromagnet-type (pull) solenoid mounted on the carburetor
> which pulls the governor arm to the idle position, and to sense when there
> is weld current, in which case it deenergizes the idle solenoid. The idle
> solenoid still works. The bad part is obsolete and unobtainable.
>
> I'm wondering if there isn't a way I could rig a remote switch to turn on
> or off that solenoid by hand. It would be a pain, but better than having
> no idle control at all.
>
> Ideas?
>
> Grant Erwin
>
normal generator to it. Just find one with automatic idle. My smaller
Generac has it.
--
Steve W.
Near Cooperstown, New York
Life is not like a box of chocolates
it's more like a jar of jalapenos-
what you do today could burn your ass tomorrow!
Jon Elson
> Mebbe take the module to a TV shop, A tech there MAY be able to 'shoot
> it and repair the problem (bad caps, prolly). If it's an IC, fergetit.
for "trade secrets" it would likely be something standard. This
sounds like a REALLY simple circuit. An op amp, maybe, senses a
small voltage across a resistor and switches on/off a power
transistor. Shouldn't need more than 10 - 15 parts.
Jon
Jon Elson
> Is the obsolete/unobtainable part a complete board or is it a specific
> part on the board? If it is a complete board, is there any information
> available on the board like maybe a schematic?
so they should have one for this module. You may have to dig
DEEP into their obsolete product files.
Jon
Grant Erwin
It's potted, and weldtron discontinued their Miller II board. :-(
Grant
Grant Erwin
I know guys who do board level work too. But this one is a module, potted in
epoxy. Later Miller boards were open i.e. repairable.
Grant
jp2express
Can you cut the epoxy off from around the module so that you can get into
it?
You could always reseal with a fresh tube of epoxy later.
Just a thought.
"Grant Erwin" wrote...
Bob Engelhardt
transformer). Remove the *primary*, put a couple of turns of welding
cable in its place. The secondary energizes a relay which controls the
idle solenoid. The trickiest part would be getting it to work with the
whole range of welding currents.
And 'course this only works on AC! Unless the leading edge of the DC
current is sharp enough to give you a pulse the could pick a relay that
would then be latched until a negative pulse on the trailing edge.
Probably not reliable enough.
Bob
Grant Erwin
There is already a weld current sensing transformer in place. I'm pretty
sure it works. It would be more of an electronics project than this thing
merits, though.
I would have thought by now that you could buy a generic infrared remote
controlled switch in about 100 different configurations for about a buck,
but nobody seems to.
I'm still probably going to cobble up a wired remote idle control toggle
switch and tape it to the handle of my stinger. If I'm up on scaffolding
and stop welding for 10 minutes to fit a part and then weld it in for 2
minutes it would be trivial to flick a switch, lot easier than climbing
down the scaffolding, walking over to the welder, etc.
Grant
Grant Erwin
> Sounds like a mess, Grant.
>
> Can you cut the epoxy off from around the module so that you can get into
> it?
>
> You could always reseal with a fresh tube of epoxy later.
Admittedly, I wouldn't have much to lose ..
it's a thought, all right. Lots of times when
modules are potted it's to prevent component
damage from vibration.
Grant
>
> "Grant Erwin" wrote...
>
>>>Precision Welder Repair has a shop in Portland they send broken obsolete
>>>boards to for component level repairs.
>>>We had some boards from South Seattle repaired there.
>>
>>I know guys who do board level work too. But this one is a module, potted
>>in
>>epoxy. Later Miller boards were open i.e. repairable.
>>
>>Grant
>
>
>
--
Pete C.
Can you provide a link to these full schematics? I didn't find them on
their site. They have the owners manuals, which include a "circuit
diagram", but that is *not* a complete schematic by any means, really
just a wiring diagram.
Jon Elson
Yup, it looks like there have been some changes in the web site. I was
there maybe 2 years ago, and the detailed service manuals were
"findable" on a link for service parts, I think. You had to look in a
non-obvious place, and then search through a HUGE list of PDFs for the
older machines. They had both the operator's and the service manuals in
there. I poked around for a while, found some more stuff like all the
literature blurbs on-line, but no service manuals. I'll bet they are
STILL there, but you need to know the exact URL to get to it, and they
only tell this to their authorized reps. (There's a "partner login",
maybe that's the way in, but you'd need a password.)
Jon
Jon Elson
Grant Erwin wrote:
>>> I have an old Miller welder with a bad idle control module. It's
>>> supposed
>>> to energize an electromagnet-type (pull) solenoid mounted on the
>>> carburetor
>>
>
> It's potted, and weldtron discontinued their Miller II board. :-(
OK, throw the module away and start over. Is there a separate inductor on
the welder output? Probably a chunk of laminated iron with 5 -10 turns
of one of the output lead wires wrapped around it? You can probably
work a reed switch contact in there so it gets enough of the welding
magnetic flux to close the reed contacts. Then, you need a simple
transistor circuit to turn on a power transistor when the switch is
open. You might add a 555 timer to delay turning on the transistor and
solenoid until there's been no weld current for several seconds.
Jon
Jon Elson
Grant Erwin wrote:
> jp2express wrote:
>
>> Sounds like a mess, Grant.
>>
>> Can you cut the epoxy off from around the module so that you can get
>> into it?
>>
>> You could always reseal with a fresh tube of epoxy later.
>
>
> Admittedly, I wouldn't have much to lose ..
> it's a thought, all right. Lots of times when
> modules are potted it's to prevent component
> damage from vibration.
If it is potted in RTV, with a plastic cover, it is quite easy to
get into it and pick off the RTV. If it is potted in hard epoxy, it
is a major hassle to get in there, and extremely hard to do so without
causing major (additional) damage.
Jon
Bruce L. Bergman
>jp2express wrote:
>> Sounds like a mess, Grant.
>> Can you cut the epoxy off from around the module so that you can get into
>> it? You could always reseal with a fresh tube of epoxy later.
>
>Admittedly, I wouldn't have much to lose ..
>it's a thought, all right. Lots of times when
>modules are potted it's to prevent component
>damage from vibration.
If all else fails, you can reverse engineer it from the bits after
you chip away the epoxy (and confirm the schematic if it ever shows
up) and make a new one.
If it's simple as it sounds, you don't need a PC Board - just a
chunk of generic Protoboard, or even point-to-point wiring if it's
only discrete components. And once it's working and debugged, pot it
again for moisture and vibration - but use clear resin so you can see
the workings next time without destroying it again.
Bump the voltage ratings on the parts, and make sure there's enough
heat sinking on any transistors - they try to skimp at OEM because
they can toss the ones that blow out and grab another from the bin,
you only want to do it once.
--<< Bruce >>--
Ned Simmons
>
>
>Grant Erwin wrote:
>>>> I have an old Miller welder with a bad idle control module. It's
>>>> supposed
>>>> to energize an electromagnet-type (pull) solenoid mounted on the
>>>> carburetor
>>>
>>
>> It's potted, and weldtron discontinued their Miller II board. :-(
>OK, throw the module away and start over. Is there a separate inductor on
>the welder output? Probably a chunk of laminated iron with 5 -10 turns
>of one of the output lead wires wrapped around it? You can probably
>work a reed switch contact in there so it gets enough of the welding
>magnetic flux to close the reed contacts.
Since (I think) this is a constant current stick welder, it might be
easier to sense voltage rather than current. Open circuit voltage is
high, welding voltage might be 1/3 to 1/2 of OCV, and the voltage will
be even lower when the welding rod touches off at idle.
One potential problem I see with reacting to current is that the
generator may not produce enough current at idle for a simple sensor
to discriminate between closed circuit idle and zero current.
--
Ned Simmons
Jerry
"Jon Elson" <el...@wustl.edu> wrote in message
news:4755A96D...@wustl.edu...
Hi Jon
Would a simple system like this work?
If I had this problem of needing to throttle up when the stick starts to
strike, I'd try to build an adjustable throttle stop that could be easily
set to the engine speed desired for the stick being used. The engine could
throttle up with a *on-off* solenoid when current is drawn. I suppose the
welding cable from the machine to somewhere near the stick holder could be
used as a voltage source to tell the throttle solenoid to pull to the stop.
Jerry
DoN. Nichols
> Sounds like a mess, Grant.
>
> Can you cut the epoxy off from around the module so that you can get into
> it?
>
> You could always reseal with a fresh tube of epoxy later.
I remember when I worked for Transitron, when a module failed
and was returned, it would be popped into a "stripper" -- a nasty
chemical which would take off the epoxy including that making the
glass-epoxy printed circuit board, leaving just the glass fibers
(loose), the circuit traces (even more loose) and the resistors (only
the carbon element and leads -- the Bakelite around them was also
stripped off (along with the color codes). You really had to know what
it looked like before potting to identify what you had. This was before
transistors started being made with epoxy cases, and *long* before ICs,
but those would have lost their case as well (along with any
indentification markings).
Later (when working for an Army R&D lab), we had something which
looked like a benchtop oven, but weighed a ton. It was a small X-ray
machine, and you would put a sheet of Polaroid film under the device
being studied. If you wanted a 3D view. you would prop it at an angle
and shoot another film, then set them in a viewer.
You still didn't have access to the part numbers on chips, but
you could at least get a good clue as to what was connected to what
before you threw it in the stripper. You could probably measure the
values of the resistors. Not sure whether the capacitors would be
capable of being measured at that point, however. :-)
And trying to get the epoxy off by mechanical means is also a
problem since it will almost certainly lose the markings on the chips --
unless you are dealing with something old enough to have metal cans on
the transistors and the chips, or ceramic packages for the chips.
I would suggest that you start with some 4x5 Polaroid film and
your friendly neighborhood dentist. (You will need the processor for
the 4x5 Polaroid film, of course. I've got one to go with my 4x5 Crown
Graphic, but I suspect that most people -- even those with a
photographic interest -- won't have them.
Good Luck,
DoN.
--
Email: <dnic...@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
gly...@gmail.com
> your friendly neighborhood dentist.
My dentist these days uses a CCD for xrays--instant results. FWIW,
the diagnostic xray we have at work also uses a CCD. You can see
inside individual chips, but mostly we use it to look at solder joints
on
ball grid arrays and to look for solder shorts on SMT parts...
--Glenn Lyford
jp2express
Hey Grant, did you follow all that? You have received some seriously
technical instructions on how to repair your part. I feel grossly
outclassed.
Happy Holidays,
~Joe
"DoN. Nichols" <dnic...@d-and-d.com> wrote in message
news:slrnflc553....@Katana.d-and-d.com...
Grant Erwin
with a chisel or something.
Grant
jp2express wrote:
--
William
"Grant Erwin" <gr...@NOSPAMkirkland.net> wrote in message
Lots of epoxy coatings on things like that ( and automotive parts ) can be
removed by a LONG soaking in methanol, heating up the methanol speeds up
the process BUT can damage the stuff your trying to see. I had a CDI module
for a motorcycle years ago that they wanted $500 for, today's value like
$2500, Anyway I dissolved the epoxy from the can it was encased in ( took
weeks) and I got impatient so I put it on the stove and gently boiled it for
the last little bit and dam if it didn't melt the electrolytic cap and made
the markings unreadable! BTW there was about 5 components on the board
total cost of about $5.00 in there.... So if your not in a hurry get a few
bottles of gas line antifreeze and submerge it for a month or so....
William...
taiken
"Grant Erwin" <gr...@NOSPAMkirkland.net> wrote in message
> I have an old Miller welder with a bad idle control module. It's supposed
> to energize an electromagnet-type (pull) solenoid mounted on the
carburetor
> which pulls the governor arm to the idle position, and to sense when there
> is weld current, in which case it deenergizes the idle solenoid. The idle
> solenoid still works. The bad part is obsolete and unobtainable.
>
> I'm wondering if there isn't a way I could rig a remote switch to turn on
> or off that solenoid by hand. It would be a pain, but better than having
> no idle control at all.
>
> Ideas?
>
> Grant Erwin
>
Grant, I still own one of those old Millers and it runs as good today as it
ever did. I did replace that idle control IC board you mention about 10 yrs
ago. I dug out my manual (1983) and and it says you need Miller Part Number
071 609. It should be available through Haun Welding Supply in Syracuse NY.
My manual also lists every diode, resistor and thyristor on the board. Tim
Grant Erwin
That's a Blue Star 2E, not a 1E, unless I'm mistaken (which I'd really
be happy to be at this point).
Grant
JTMcC
"Grant Erwin" <gr...@NOSPAMkirkland.net> wrote in message
Do you know the Miller part # ?
JTMcC.
Grant Erwin
Certainly. It's 039434. Got one? Miller doesn't ..
GWE
JTMcC
"Grant Erwin" <gr...@NOSPAMkirkland.net> wrote in message
No I don't.
Western States Welder Repair sells several discontinued boards including the
Miller 038472. You might have some luck talking to them. 970-243-9616.
good luck,
JTMcC.