TSSP: List Archives

From: boris petkovic
Date: Sun, 13 Oct 2002 13:21:02 -0700 (PDT)
Subject: Re: [TSSP] Top Voltage


--- "Terrell W. Fritz"  wrote:

> 1Hz single shot mode and the 52uS dwell don't really
> match well.  So I
> turned the dwell knob to 500uS to really drain the
> system:
> 
> http://hot-streamer.com/temp/OLTC10-12-03.gif
> 
> First I was stunned at how many primary to secondary
> notches I was
> getting!!  Note - need to check Q again...  Now more
> energy should be
> getting to the top terminal and all.  However, the
> breakouts were just as
> rare!!  Nothing really seems to have changed as far
> as breakout
> "quality"...  300Volts firing voltage and 3 amps
> peak secondary base
> current....
---
1 shoot per second you say.If the polarities of each
primary excitation are to be considered that may also
have some impact to breakout discrepancy.
1 sec from shoot to shot is a long time and acumulated
space charge should greatly "dissipate" around sphere
terminal by electrostatic repulsion and other
neutralisation mechanisams.
DC operated TC and AC operated TC brekout potential
can differ in higher BPS run modes but 1 Hz..
---



> 
> I must wonder if the odd things we see are well
> known.  I used to work on
> 340kV power lines (60HZ) that were about 1 inch in
> diameter...  I never saw
> any "breakout" from them....????  Hmmmm,  There must
> be some great truth
> there we are missing!!!   That always confused me
> and I never found the
> answer to that one over the years...
---
Oh ,there is no big mistery about that one.
I saw your question on pupman and decided to reply
here
(TCML is too loaded anyway).
You are comparing spherical field and cylindrical wire
above plane field  in a very bad manner.
1" sphere  will have much higher surface field
(multifold) for given voltage than 1" thick wire
(which is long ,"perpendicular" to ground plane (at
average height say 10 m).
There's no 10X overstress filed in 340 kv power lines
case you mentioned .
HV lines (especially if more conductors per phase)
would have 40..50 kv/cm (in worst cases) max stress
field and I guess they are designed bellow that
ballpark to operate continiously at 60 Hz.      
During bad weather ,or somewhere locally they emit
corona thou.
---- 

> Of course, the running Q now is about 94 :-))))  I
> have no idea why....  At
> 250 volts I (the scope) took 64 readings and there
> were 4 breakouts.  At
> 300 volts there were 6 breakouts.  I did note that
> the breakouts seem to
> occur soon after the coil was turned on and then
> stopped. 
---
Space charge DC vs DC already mentioned issue perhaps?
If correct.Gee..at 1 Hz..
---


 After the 300
> volt run, I "wandered" around in there feeling the
> coil and surroundings
> for residual charge.  I could detect nothing. I am
> not a sensitive
> electrometer or anything, but I sure didn't feel any
> hair standing on edge
> stuff...
---
Well ,I suppose humans are not that sensitive (Hmm
maybe some individuals ala Tesla are).

--
  
> So, probably more questions than answers here ;-)))
> 
---
In my native langue there is  expression:
"Zaklela se Zemlja Raju da se sve tajne odaju".

Cheers,
Boris

__________________________________________________
Do you Yahoo!?
Faith Hill - Exclusive Performances, Videos & More
http://faith.yahoo.com


Maintainer Paul Nicholson, paul@abelian.demon.co.uk.