Had a learning experience with my welder, just thought I would share, (engine drive)

[BHD]

Bought a new welder, about a month ago, and was welding great, I had a small project, I needed to weld, and the welder would not weld, finally I turned it up to max and got the mower deck welded,

so I call the dealer, and called the service number no help but to give me a name of a repair shop, so I call the repair shop and talked about the problem, some more check this check that, and a small discussion on the rheostat, no more ideas, but bring in on Monday, OK,

so I take some more tools and find a cycle meter, to see if the engine is at the correct RPMs, and try the DC reverse and straight and the AC setting, could get a bead on DC and nothing on AC.

during the night I got thinking is the remote switch setting, (sure enough my little goats were on the truck and flipped the switch), OK now it welds on DC correctly but still no AC or nearly no AC, I called the welder repair guy on the week end and he has no ideas, I said I would call Monday if I am coming or not, and remember a time when a large welding shop was having problems with a welder and for some reason they wanted AC, out,
and asked if I had reels on the leads, and I do, well on AC the coil some how reduces the out put,

I unroll the leads of the real and it works great, apparently on DC the effects on the reels is not as great, (something to do with the DC and not working as a transformer, and on AC works as a transformer),

there is an effect on DC, but just as not as great, as on AC. but was amazed on how it reacted on AC setting,
apparently the same can happen if there just wrapped or even rolled up on the ground.

~~~~~~~~~~~~~~~~

well I learned some thing this last weekend,

check the remote/local switch, and if needing AC do not have the leads on reels,

 

[Botaskinner]

reminds me of what happened at a manufacturing plant I worked in. Right outside my office was a TIG weld station, and the operator had coiled (about 10 turns) his torch lines on an overhead bar that pointed straight at my desk on the other side of the wall.

One day he hit the pedal welding some 1/4" aluminum, and I ended up with a torrent of gibberish on my computer screen every time he did so..the TIG line was acting as a giant solenoid winding, throwing interference right at my monitor. We had to reorient his lines and that day on, heavy aluminum welding was done a couple of bays down.

In your case because it's AC maybe coiling the lines causes some of the current strength to be cancelled out? I'd like to know.

 

[CobyRupert]

Coils = "Inductor" (or "reactor", or "choke").
Note A.C. current is always changing (i.e. alternating)

From Wiki (Inductor - Wikipedia, the free encyclopedia "When the current flowing through an inductor changes (i.e. A.C.!), the time-varying magnetic field induces a voltage in the conductor (or across the coil)...; ...the direction of induced electromotive force (or "e.m.f.") is always such that it (inductors) opposes the change in current that created it. As a result, inductors always oppose a change in current, in the same way that a flywheel opposes a change in rotational velocity. Care should be taken not to confuse this with the resistance provided by a resistor."
"Inductors are widely used in alternating current (AC) electronic equipment, particularly in radio equipment. They are used to block AC while allowing DC to pass; inductors designed for this purpose are called chokes."



Basically this opposition to current (impedance) follows Ohm's Law: a voltage forms across the impedance (the coil), thereby cutting the voltage seen at the end of the leads, and/or increases the total circuit impedence, cutting the amperage. But unlike a resistor where heat is created, a magnetic field is created at the inductor (coil). In some applications, this magnetic field is used to transfer energy (example: mechanically in a solenoid (or relay) to create an electro-magnet that attracts it's mechanical plunger, or in a transformer to induce a magnetic field on the secondary windings (i.e. coil) and "reverse-convert" it to a secondary voltage), or in a motor to pull-push (spin) the rotor.


Basically the coil / inductor / choke will limit A.C. current. It's just like a dimmer switch for your incandescent lights. A way to cut the voltage to them by creating a magnetic field (and voltage drop) at the dimmer (coil), rather than generating heat (like a "resistor" would do).


(Yes, I know, the term A.C. current is redundant!!)

 

[k0ua]

In my opinion these concepts of inductance, capacitance and resistance along with Ohm law should be taught in about 9th grade science. It would take less than a week of the curriculum and would give a lifetimes worth of useful knowledge applicable in the real world to the populace.

It is a darn good thing that I am not a educator, or you would have this info shoved into your brain at an early age.
We would also do some fun experiments like taking a 9 volt battery and placing it across an inductor (an old transformer primary winding will do) and then removing the battery. A nice lesson in collapsing magnetic fields would be learned. I learned all about it the hard way at about age 10.

 

[BukitCase]

James, so did I - I can testify from first-hand experience that drawing a spark about 3/4" long is a MUCH more effective method of learning/retention than just reading about it in a book ...Steve

 

[k0ua]

James, so did I - I can testify from first-hand experience that drawing a spark about 3/4" long is a MUCH more effective method of learning/retention than just reading about it in a book ...Steve

You should have seen my eyes light up when I got the He77 knocked out of me with a 9 volt battery. I just had to know why. I have been learning every since.

While we are telling stories, when I was about 14, one of the more devious guys on our bus asked me if I would like to look at his little silver book entitled "Female Sexual Behavior". Sure said I, and when he handed it to me it just about flattened me and he said "Shocking isn't it?" I replied it sure was! The silver on the books front and back was apparently aluminum foil and inside was a rubber band powered spinning piece of metal that intermittently made contact with an inductive coil and a small battery. So this was basically a spark coil.
With the metallic covers of the book held in my sweaty eager little hands I could see my life passing by my eyes. I swear that thing was as bad as any electric fence that I ever got hung on. The current path was right thru the old ticker too. Too much fun, I bet you cannot sell such a death machine nowadays.

 

[dickfoster]

In my opinion these concepts of inductance, capacitance and resistance along with Ohm law should be taught in about 9th grade science. It would take less than a week of the curriculum and would give a lifetimes worth of useful knowledge applicable in the real world to the populace.

It is a darn good thing that I am not a educator, or you would have this info shoved into your brain at an early age.
We would also do some fun experiments like taking a 9 volt battery and placing it across an inductor (an old transformer primary winding will do) and then removing the battery. A nice lesson in collapsing magnetic fields would be learned. I learned all about it the hard way at about age 10.

I agree. As important as electricity and electronics is in the world today is most people are still befuddled and mystified by it. That's a real shame when it's really pretty simple stuff.

Got my first warning from the FCC at age 12 for building a crude spark gap jammer which they tracked down with a directional finder. "Them: What are you kids doing? Us: nothing just playing" My dad was not amused and let me know in no uncertain terms. Arcs and sparks wipe out pretty much the entire spectrum, AM, FM, TV, Ham bands all get stomped on. LOL

 

[woody]

You should have seen my eyes light up when I got the He77 knocked out of me with a 9 volt battery. I just had to know why. I have been learning every since.

similar thing happen to me I was about 12 years old and my dad bought a house while moving stuff out of the old garage my finger went in a wall plug with out a cover on it and I was formally introduced to a 110 volts AC. I then spent the next 45 years working with electricity in some form or fashion, like you said I just had to know.

 

[stuckmotor]

James,
You're always teaching me something. That electrical book sounds like a package my uncle was passing around when I was a little kid. My mother wouldn't let me near it, but I think about it from time to time. Now I know how it worked.

 

[k0ua]

I agree. As important as electricity and electronics is in the world today is most people are still befuddled and mystified by it. That's a real shame when it's really pretty simple stuff.

Got my first warning from the FCC at age 12 for building a crude spark gap jammer which they tracked down with a directional finder. "Them: What are you kids doing? Us: nothing just playing" My dad was not amused and let me know in no uncertain terms. Arcs and sparks wipe out pretty much the entire spectrum, AM, FM, TV, Ham bands all get stomped on. LOL

Somewhere around here I kept a defective power supply from piece of networking equipment. That thing wipes out the entire spectrum when it is plugged in. I think if you put a good antenna on it and keyed it on and off you could make long distance contacts with it. I have never seen a switching power supply put out so much Radio Frequency energy. I have no idea what is wrong with it, I just noticed it one day when I turned on my Amateur radio transceiver and noted that all band were wiped out by this noise source. I tracked it down to something in my own house and went to flipping breakers. The supply was still powering the piece of equipment (data switch) but boy was it ever making the RFI.