Re: Vacuum/blast gap

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Stacy Gillett by way of Terry Fritz <twftesla-at-qwest-dot-net>" <sgillett-at-hotmail-dot-com>

Hi Steven,

On my coil, I have tried the RQ gap with some gentle airflow from a 
microwave oven fan, as well as the sucker gap with a 900VA vacuum motor:

http://hot-streamer-dot-com/stacy/RQgap.jpg

http://hot-streamer-dot-com/stacy/vacgap.jpg

Apart from the noise they make (the sucker gap makes a "sizzling" noise 
compared to the lower growl of the RQ gap), they both result in roughly the 
same streamer length and intensity from the coil.  Both gaps were set at 
about the same spacing (0.25")

How large are your sucker gap electrodes?  I use 20mm brass all-thread and 
reducers with 900VA of input power, and with the vacuum running full blast, 
they stay cold even minute-long runs.  I would imagine that smaller 
electrodes that can't sink as much heat could have an effect on performance.

I also noticed that, running the coil on the sucker gap without the vacuum 
turned on, performance was terrible!  While I was getting 36" or so with 
airflow, this dropped down to less than an inch without airflow (basically 
topload corona and little else).  It seems that getting the right amount of 
airflow is pretty crucial to the coil's performance.

By the way, I've noticed that descending multi-note whistle when the vacuum 
is turned off as well --- now I know it's not just a quirk of my own coil 
:-)

Stacy.


>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Vacuum/blast gap
>Date: Sun, 15 Sep 2002 12:47:17 -0600
>
>Original poster: "Steven Ward by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
><srward16-at-hotmail-dot-com>
>
>Hi all,
>
>I recently attempted to reproduce Gary Lau's sucker gap.  I bought the same
>vacuum motor.  My meter claims 3A for the motor, yet Gary claims about
>10A?!?!  Thats not what im getting at.  My problem is that this gaps 
>stinks!
>   Of course, i could have made it differently, but it doesnt perform 
>nearly
>as well as me RQ gap.  Though, i must say, it makes the coolest noises when
>you turn off the coil, and you hear all kinds of pitched wistling from the
>motor.  It sounds real sci-fi, like a major shut down.  Im running with a
>15/120 PSU.  Im wondering it anyone has used this type of gap, but with air
>blowing outward??  So basically, i need some ideas, or reccomendations, on
>what i should do.  Sould i keep the RQ and put the vac motor on it??  Or
>should i make the single gap, but blow out the arc, rather than suck it up?
>All opinions are wanted.  Thanks,
>
>Steve Ward.
>
>
>