Build your own
It was written: >I saw this at a local pawn shop yesterday: Sears Hi Frequency >Arc Stabilizer, prim volts: 115 VAC, Sec. volts: 3500. He wants $150 >for it. I have no use for it myself, plus don't have the $$. If >anybody wants it, let me know. I "discovered" modern tesla coiling via some research into just this sort of device. Basically what you will find inside is nearly an entire tesla primary circuit. Neon, cap, gap, and output coil ("primary"). This box still sells for something like $750 new out of the Sears Industrial catalog. Not a bad markup for something your average coiler could scrounge for about $50. :) This device is designed to superimpose a High Frequency/High Voltage (generated by the gap/cap/primary) onto the welding current, supplied by the welder you'd attach the box to. Weldors (folk who weld) like this since it eliminates having to manually "strike" the arc - the HF/HV does that for you (by ionizing the air) once the welding rod approaches the work. To some extent, using this device will allow you to do a limited amount of TIG welding using a stick welder for a power supply. Of course you still need an inert gas supply, etc for the TIG. I finally did discover what type of ferrite cores to use in my homemade coupling transformer. The core is important not due to it's effective permeability (the core raises the primary inductance by a factor of only about 2). However, the core greatly increases the coupling between the two coils by (?) causing more of the flux to link the output coil. In a situation like this (I think) you want as high a coupling coefficient if possible. Turns ratio is 1:1 and there is no use of any resonant rise phenomenon since output capacitance is variable and unknown. My TIG arcstarter runs on the live half of a half-dead 12000v 30 ma neon, using a 4-gap @ 0.028 RQ with fan, and only about 1500 pf of capacitance (doorknobs). The output will pierce vinyl electrical tape, or jump over 1/2 inch under argon, which is more than sufficient for my purposes. If anyone has any questions feel free to contact me. One of these days I'll get it all on the page, but don't look there just yet!Here is MY setup:
Here are three scanned pages - which started it all...
a) Decrease the intensity of the current to reduce power* I have a small 500 pf HV cap (C2) across the output of the transformer to work as an LP filter. This will extend the life of the transformer.
b) Extend capacitor life
c) Extend spark gap life
-Bill the arcstarter - experienced amateur weldor "I'll try to weld anything!" Starting arcs in Cinci, OH http://www.geocities.com/CapeCanaveral/Hangar/6160Return to The Arcstarter Page