welder idle control?

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

Reply to
Jerry
Loading thread data ...

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.

Reply to
DoN. Nichols

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

Reply to
glyford

Dang!

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

Reply to
jp2express

Yup. Way over my head. I might pull the part and hit the potting compound with a chisel or something.

Grant

jp2express wrote:

Reply to
Grant Erwin

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...

Reply to
William

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
Reply to
taiken

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

Reply to
Grant Erwin

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.