EGAD !!! I've been pursuing some homework across the expanses of the 'net, and there must be a zillion different ways to build the circuit to do what I originally sought...

I did finally find a circuit I could live with, and make some minor modifications to for several different frequencies, using parts I wouldn't have to mortgage the house to obtain...
Will keep this current as the circuit starts to take shape...

attached, for the heck of it, is one of my favorite electrical passtimes... rewinding microwave trannys... the yellow, is #18 w/ teflon insulation, held in place by epoxy.

Another is in progress of becoming a sheet-metal shop level spot-welder... I will be using the same approach to make a small spotwelder of sorts, to apply conduction strips to various L-ion and NiMh batteries...

 

I see that you, like me, are opposed to cutting open the transformer with farmer's tools. Here's some inspiration for your spot welder:

 

Iwould cut the weld one that has not got the "E" laminations, conversely the style that the top is all the closure bars [ terminology ?] Reason is, I only have an old 110v "buzzbox " welder, that does a sloppy job..
[ [ Who ME ?"? ] ]

That is one helluva nice console you got there !!! and that spotwelder is very unique !!!... How long of a cable can I get away with for the handpiece like that ??

 

How long of a cable can I get away with for the handpiece like that ??

Depends how many amps you want to get out of it. When you're talking 3,000A @ 4V, every insignificant smidge of resistance counts. The longer you want your leads, the fatter (really fat) they must be. My leads have a cross-sectional area of about 1.5 sq in. I tried several configurations until I settled on this one; it was the only one that allowed me to pass such a huge amount of copper through the transformers. All the other configurations required smaller copper cross-section, which limited my amps.

If I had it to do over again, I would use more flexible cable. I would strip the insulation from several heavy duty jumper cables or welding leads and combine them. As it is, I used so much solid core wire (stripped Romex) that my leads barely have any flex, which totally negates the purpose of having long leads. I was supposed to be able to get into tight spots with this, but I can't.

 

Depends how many amps you want to get out of it. When you're talking 3,000A @ 4V, every insignificant smidge of resistance counts. The longer you want your leads, the fatter (really fat) they must be. My leads have a cross-sectional area of about 1.5 sq in. I tried several configurations until I settled on this one; it was the only one that allowed me to pass such a huge amount of copper through the transformers. All the other configurations required smaller copper cross-section, which limited my amps.

If I had it to do over again, I would use more flexible cable. I would strip the insulation from several heavy duty jumper cables or welding leads and combine them. As it is, I used so much solid core wire (stripped Romex) that my leads barely have any flex, which totally negates the purpose of having long leads. I was supposed to be able to get into tight spots with this, but I can't.

I have been looking at #4 stranded, maybe even professional double-aught jumper cables, or arc-welder cable... One of those, carries some bodacious amperage...

The only caveat, is could I get a whole loop of 0 or 00 in the limited secondary passages ? I hooked it up static with some #4 Range wire, and welded two 16-penny nails together, which only fueled my urgency to get this project off the " breadboard " and functional. My other concern, is over-drawing the primary