Jon Elson wrote:



Ignoramus26745 wrote:

I made a homemade TIG torch cooler, from a used carbonator pump from
soda fountains. Pictures of the pump, solid state relay, etc, are
provided.

Also provided are pictures of the innards of my welder.

The story is he

http://igor.chudov.com/projects/Weld...-Torch-Cooler/




Hey, I thought you said a couple of weeks ago that it did NOT have HF.
Obviously, in the lower left corner of the pics of the welder's innards,
is the HF section. Maybe you meant it wasn't working, I don't know.
I have to say the inside of my Lincoln Square-Wave TIG 300 is a lot more
organized than the Hobart. There is VERY little wiring in the main
welder section other than the main power cables. All the circuit boards
and interconnect wiring is in an enclosed space behind the control panel.
I'm almost amazed the Hobart works at all with all the control wiring
hanging out near the main power circuitry. (I do notice a big shield
between the HF and the control boards. By the way, you may be
breaking the shielding with your new wires for the cooler. They go
right by the HF section, then up near the control boards. I would not
route them that way.)
I agree: I would not run any wires into that bottom box (with the HF) if at
all possible, and if I really did need to run wires into that box, I would
keep them clipped to the metal wall so as to be as far as possible from the
HF coils, and to minimise the flux flowing in the loop between the wire and
the metal wall. Certainly don't try putting any of your new circuitry into
that box with the HF. I think the top box looks more promising as a place
for the new circuitry. By the way, you could water-cool the IGBTs, that
works really well as long as you put a safety thermal switch to shut things
down if the water stops. The method I prefer is a slab of copper busbar
maybe 3 inches wide, quarter inch thick and as long as needed to bolt down
all the IGBTs. First drill and tap it for the IGBTs, mounting holes etc.
whilst it's still hard copper and easy to tap. Then use silver solder (not
soft solder but the sort that melts when it is almost red hot) to attach a
zig-zag of maybe quarter inch diameter copper pipe to the back of the
busbar, trying not to get solder into the holes you tapped before. Make
sure that the copper pipe fits well to the back of the busbar before
starting to solder it. I would also recommend making the ends of the
copper pipe long enough so that they protrude outside the welder and there
are no joints in the plumbing inside the welder casing. This way, if you
make the pipes slope downward, then if the joints in the pipework should
leak, the water will stay out of the wiring. You can get rid of several kW
with this sort of water cooling.

Chris


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