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Jon Elson

wrote:
Hi,
I'm currently building a complete WIG/TIG welder... microcotroller PCB
is runing and will be programmed probably next year (takes some
time ;-)
Currently I'm working on the arc starter.
I found an television high voltage transformer which has its resonance
frequency at 310kHz.. .I don't know why, but thie high frequency
works.
I get 3..4 cm at 12V and 2A... really lucky about that.
But I still failed to make the couppling from HV-side to the LV
welding lines.
There are several pictures available in the web with eg 20:20 turns...
every link says ... its running perfectly.
Here how I tried...
make 20:20 turns air coil with a diameter of app. 15mm...
connect one HV wire directly,
the second with a 1cm gap (no cap!)
The typical TIG HV system has an old-style tesla coil circuit,
with a 10 - 20 turn secondary that the torch lead is connected
in series with. This produces a few hundred volts open-circuit
and adds it to the torch open-circuit voltage.

Jon