Re: contact spark gap VSVFSQ

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: gary350@xxxxxxxxxxxxx 


I posted this about 6 or 7 years ago here goes again.  Build yourself 
a VSVFSQ, Variable Speed Vaccuum Fan Spark Gap it works just as well 
as a rotory spark gap and it is much easier to build and costs 
less.  I built my first rotor many years ago rotated the motor to 
sink the gap got is adjusted for max output and it was working 
great.  Later I built a VSVFSQ and found it worked just as well as 
the rotor.  I posted the info here and Rickard Hull once said a rotor 
is just a fancy toy a well tuned spark gap works just a well. The 
VSVFSQ can be used on any size TC from 400 watts to 15KW.  It is 
nothing but an RQ gap with a vaccuum fan and a variac.  The cool 
thing about the VSVFSQ is you can turn the variac and watch the 
streamers get longer and shorter as you make adjustments.  A streamer 
can increase in length by 30% just by changing the fan speed.  The 
attached link shows my first VSVFSQ.  I have several of these I later 
discovered the air slots in the side are not needed.  It actually 
works fine just to let the fan suck air in the end of the 4" PVC pipe 
and over the gaps. Get you a $2.00 vaccuum cleaner at a yard sale or 
salvation army store remove the fan motor and build one.  As I recall 
I bought 6 fans from H&H for $10.00 each about 7 years ago.


http://s43.photobucket.com/albums/e358/gary350/?action=view&current=gap-1.jpg


http://s43.photobucket.com/albums/e358/gary350/?action=view&current=gap-2.jpg




-----Original Message-----
>From: Tesla list <tesla@xxxxxxxxxx>
>Sent: Apr 13, 2007 11:49 PM
>To: tesla@xxxxxxxxxx
>Subject: contact spark gap
>
>Original poster: "Scott Bogard" <teslas-intern@xxxxxxxxxxx>
>
>Hi everybody.
>     Since everybody is talking about spark gaps, I figured I'd throw
>out an idea I've had rolling around in my head for a while.  A spark
>gap has losses in the spark, but solid state cannot handle the raw
>power a spark can (not yet anyway), so what if we eliminate the
>losses by having direct contact, and eliminate the power issue by
>dumping the semiconductors?  Here is my idea, take a rotary spark
>gap, and cut the disk mounted electrodes flush with the disk surface,
>then mount brass bushings between two shafts, pinching the disk
>between them.  As the disk turns it will make contact with the
>bushings and complete the tank circuit, dumping loads of power into
>the primary.  The obvious problem with this is it will arc before it
>rolls over the contact defeating the whole purpose, but my thinking
>is you could use a smaller rod to increase "quenching" and submerge
>the whole thing in mineral oil to keep stuff cool and cut down on
>spark, but you will need a really tough motor.  Has anybody out there
>tried this already?  would there be any benefit?  would it be as
>difficult to build as I think it would be?  Just curious, thank you much.
>Scott Bogard.
>
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