Re: 'true" spark length was Re: Desktop Bipolar Coil

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

Original poster: "Bert Hickman by way of Terry Fritz <teslalist-at-qwest-dot-net>" <bert.hickman-at-aquila-dot-net>

Ralph and all,

There may be a couple of factors at work here. Water vapor does act as a 
fairly efficient electronegative gas - its presence in air tends to further 
reduces the lifetime and availability of the free electrons that are 
essential for spark formation and propagation. At high humidity levels in 
the presence of surface dust a thin "monolayer" film of water can form on 
the surface of the coil form. When combined with surface contaminants, 
leakage losses will increase in the secondary winding.

Under worse case conditions with coils with relatively large ROC toploads, 
breakout may actually be inhibited on damp days. This was one of the 
symptoms I observed on rainy days along with reduced streamer length. Dry 
days or cold and dry (winter conditions) always resulted in better performance.

Best regards,

-- Bert --
-- 


Tesla list wrote:
>Original poster: "Ralph Zekelman by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <gridleak-at-bluemarble-dot-net>
>Jim,
>I operate my coils in the basement. I run a dehumidifier constantly in
>the summer and that keeps the large basement dry. I see a difference of
>almost ten inches with humidity changes. Corona is a major loss and is
>reduced
>by a low humidity.
>Ralph Zekelman
>-----Original Message-----
>From: Tesla list [mailto:tesla-at-pupman-dot-com]
>Sent: Wednesday, July 02, 2003 8:19 PM
>To: tesla-at-pupman-dot-com
>Subject: Re: 'true" spark length was Re: Desktop Bipolar Coil
>Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>"
><jimlux-at-earthlink-dot-net>
>  > system or, to put it another way, a rather low output voltage/energy
>  > storage ratio in the secondary. I dare say the result was also
>  > dependent to a degree on the humidity content of the air at the time
>  > (I recall it as being rather low).
>  >
>  >From a purely theoretical standpoint, I wouldn't expect humidity to
>have a
>huge effect.  Humidity has a big effect on static electricity machines
>where
>you depend on a very high surface resistivity because the charging
>current
>is so low.  On a TC, though, you've got energy to burn, and corona is
>probably a bigger loss source than leakage.
>
>.