[Prev][Next][Index][Thread]

corona discharge expermnt

 * Original msg to: P.l.mason-at-bath.ac.uk
 * Carbons sent to: usa-tesla-at-usa-dot-net

Quoting Richard Quick:

 > My first electrical project in my new house was setting a      
 > small 1/2 wave Tesla coil system up inside of the              
 > refrigerator. I used two aluminum pie pans for the end         
 > terminals on a tiny coil wound on a 12x3 inch PVC pipe (junk   
 > box), two spark plug gaps, about .002 microfarads capacitance, 
 > a single 9kv 30ma neon power supply. It took about an hour to  
 > set up. I tuned the coil so corona would illuminate the space  
 > between the two pie pans. With the refrigerator closed and     
 > running I would energize the coil and let it run for five      
 > minutes, then shut it off for 15 minutes. I did this most of   
 > the afternoon yesterday while unpacking. Before I went to bed  
 > I let the thing run for about 15 minutes straight. R. Quick

Quoting P.L.Mason-at-bath.ac.uk:

> Would you please post a few more details on this coil, like how
> many turns, and the primary configuration? It sounds like the 
> primary goes in the middle? What sort of sparks could you pull
> from it?   Phil

I never thought I would be asked to post on this junk box coil. 

The secondary coil looks as if it is wound with #30 AWG magnet
wire close wound over 12.5 inches of thick wall 3 inch diameter
schedule 40 PVC pipe. I wound this coil so many years ago that it
is but a dim memory, even the last time I tried to fire it. I
wrapped it up in a few turns of paper to protect the winding and
it has been in the bottom of my "junk coil" box for well over ten
years.

I took a three inch long ring cut from some 4 inch diameter PVC
drain pipe and placed it around the middle of the coil described
in the paragraph above. I held the ring in place by stuffing the
gap with styrofoam (polystyrene foam) packing "peanuts" used by
commercial shippers. This outer ring made a rough coil form
around which I wrapped 1.5 turns of battery cable. I held the
whole thing together with a few wraps of black friction tape. 

The pie pan electrodes are the kind used for single serving
chicken "pot pies". The flat bases of the pan are about three
inches in diameter. I used plastic clothes pins to stand them up
and place them so the smooth bottoms were faced off:              


                 \              /                                 
                  \           /                                   
                   \        /                                     
                   |       |                                      
 "pot pie" pan>    |       |     < "pot pie" pan                  
                   |       |                                      
                   |       |                                      
                  /         \                                     
                /             \                                   


The primary capacitance was two .004 microfarad barium titanate
capacitors placed in series, it was probably closer to .0015
microfarads capacitance total. The spark gap consisted of two NGK
automotive type, non-resistive, spark plugs placed in series and
gapped at about .040 inches each.

This junk box oscillator/resonator set took about an hour to
assemble, most of that time being spent digging through my
electrical junk boxes looking for the parts, assembly only took a
matter of minutes. It was wired with clip leads except for the
primary. I really did not have to tune much, it seemed to do the
job I needed as soon as I fired it up. Most of the adjustments
required were to prevent shorts, loose connections, and arcing to
the refrigerator interior.

I never attempted to see how much spark I could get. I was able
to ionize the air gap between the bottoms of the two pie pans,
which was indicated by a nice violet corona. This was achieved 
when the pans were gapped at about ~ 2 inches. This corona gap
was placed directly in front of the refrigerator circulating fan
which removed the ozone produced in the gap.

Richard Quick


... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12