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Re: Advanced Spark Gap Technology
At 10:32 PM 2/3/00 -0700, you wrote:
>Original Poster: gweaver <gweaver-at-earthlink-dot-net>
>
>I have been experementing with spark gaps. I made several paper funnels to
>reduce the area of a box fan and increase the air velocity. I reduced a 4"
>box fan down to 3", 2", 1.75", 1.5" and I checked the air velocity with the
>air flow meter that I borrowed from work.
Which one worked the best?
>I built a spark gap using 10 flat copper plates 2" x 2" each. The copper
>plates are made from roofing flashing from the lumber yard. I cut the
>plates with tin snips and filed the edges smooth. I clamped all the plates
>together in a stack and drilled a .150 diameter hole threw the entire stack
>of plates in each corner. 4 places.
>
>I flattened each copper plate by placing it between 2 blocks of steel 1"
>thick 2" square and hitting it with a 2 pound hammer.
>
>I used 2 paper punches to punch out some .006 mil polyethylene flat washers
>with a .150 diameter hole in the center. 4 washers in a stack gives me a
>.024 space between each plate. I put spacers on all 4 corners. Its all held
>together with 4 plastic screws with plastic hex nuts on each corner.
>
>The finished spark gap is about 1/2" thick 2" square with a wire soldered on
>each outside plate. The spark gap is taped to the end of a paper funnel and
>the funnel is taped to the end of a box fan.
>
>I ran this for about 20 minutes on a 750 watt coil and it works better than
>my RQ gap with the same box fan. The flat copper plates act like a radiator
>and keep the spark gap cool. The air tends to blow most of the sparks to
>the back half of copper plates.
>
>Its small, compact and easy to build. I think it would be easier to build
>if the plates were made out of thicker metal so they won't need to be
>flattened. Some 1/16" aluminum plates will probably work fine. Wires can
>be attached to stake on terminals and put under the head of the plactic
>screw on one plate and another terminal under the hex nut on the other plate.
I've thought about building gaps like this a lot, especially after reading
old articles about building quenched gaps and stuff like that, but I never
could think of a spacer that wouldn't end up either conducting, getting a
carbon track, or breaking from heat-stress. The old designs used mica as
the spacer. But shoot, even if it *did* track, it would be so easy to fix...:)
I think I'll give this a shot. Could you describe the fan/funnel/gap setup
a little more?
Thanks,
Dan
>Gary Weaver