Re: Question on Ceiling Height/Material

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "James Zimmerschied" <zimtesla@xxxxxxx>

hello Terry, Bart  and all,
I was out of town attending a funeral so I am behind on the ceiling 
height conversation.

I did take the coil home and tried it in my garage on the same day- 
it didn't start making sparks until I had loaded it with massive top 
loads - and still not smooth as at the other location. My conclusion 
was I needed to push the secondary frequency lower to correspond to 
the trigger circuit frequency. Also I need to add some primary turns 
for tuning.

Tomorrow I plan to return to the low room shop and try again. If 
there is time I will take some equipment to measure Fres and compare 
with the calculated value.
Jim
----- Original Message -----
From: <mailto:tesla@xxxxxxxxxx>Tesla list
To: <mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx
Sent: Wednesday, May 24, 2006 11:23 AM
Subject: RE: Question on Ceiling Height/Material

Original poster: Vardan 
<<mailto:vardan01@xxxxxxxxxxxxxxxxxxxxxxx>vardan01@xxxxxxxxxxxxxxxxxxxxxxx>

Interesting....

His is a primary feedback system very close to this schematic:

<http://hot-streamer.com/temp/DF-DRSSTC-SCHEMATIC.pdf>http://hot-streamer.com/temp/DF-DRSSTC-SCHEMATIC.pdf

I must wonder too if the problem is not a loose wire or some other cause...

I suppose the feedback coils sort of automatically "adjust" to a
point...  Interesting...

Cheers,

         Terry

BTW - The inductor I made for the SISG MOT system would be good for
the DF-DRSSTC *:-)))  But maybe the DCR is too high.....??

At 12:08 PM 5/24/2006, you wrote:
>With a feedback driven system, i don't see proximity effects changing
>the operating parameters so much as to not make it work, assuming of
>course you are driving it with feedback.
>
>Dan
>
>
>
>
>I recently noticed that the ceiling height and material can make a
>significant difference in a coil's secondary frequency.
>
>Case in point - I was trying to get my DF-DRSSTC working. I couldn't
>get it to break out properly and it was drawing too much current. I
>took the coil over to a friend's house and it was working well - got
>18" arcs to a ground rod - with no change in the coil configuration.
>What was the difference? My friend said his shop which has a flat
>metal roof, suppresses the operating frequency of his coils. When he
>moves them outdoors, they have to be retuned. When I was trying to
>run this coil before, I was in my garage which has no "ceiling" only
>open rafters up to the roof.
>
>In playing with parameters in JAVATC, I see a noticeable change
>between an 8 ft ceiling and a 12 foot ceiling. I don't see anything
>in the program that inputs the material type for the ceiling. I would
>think a non-conductor like gypsum wallboard would have less effect
>than a flat steel roof. Maybe Bart could shed some light here.
>
>The bottom line for me is to accurately model the room envelop when
>running a TC modeling program. Also, if you relocate the coil - say
>from in the garage to out on the drive way - expect to have to retune
>(possibly reconfigure).
>
>Jim Zimmerschied