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Primary field strength
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From: chris.swinson [SMTP:chris.swinson-at-zetnet.co.uk]
Sent: Friday, August 14, 1998 3:20 PM
To: tesla list
Subject: Primary field strength
Hi all,
I discovered today that my coil's field strength drops off at about 38". I
used a 8Kv 30ma NST. My secondary ( 38" ) and cap ( 11.45nf ) were not used
at first. This gave me a clear indication that the field rose to a hight of
38". I could gain about another 2" spark if a increased the coil's length
but thats not the issue here.
When I tried a 6.4nf cap, with only 1mm spark gap, The field was so big that
it filled the whole room. If I had used a 5mm gap ( about max ) Wouldn't it
be possible to have a secondary say 200" in hight and still power it off the
8Kv 30ma source.
The secondary would still be in the field of the primary as the cap give's a
high current boost each cycle.
But even so, why am I told not to go over 24" for my secondary height ?
The only problem I can see is the resistance of the secondary would be huge
due to the extra wire, but I can double wind my coil to get around this. So
in fact I could get about a 72" spark off a 200" coil, with the power still
being only 8Kv -at- 30ma.
I know Tesla used large inductive coils, perhaps he did this to use bigger
caps and get better effieciency.
The only other drawback being the frequency would drop due to the high
inductance, but my specualted coil at 200" high, would only give 44mH
inducatnce anyway. My 36" coil is only about 8mH anyway. So the way I see
it, its a win-win situation.
Can anyone confirm this or have anything to comment on ?
By the way, I'm a bit think, so whats BTW stand for ? Its driving me mad !
All the beST,
Chris.
chris.swinson-at-zetnet.co.uk
www.users.globalnet.co.uk/~mega01/ <--- moved site to...
www.users.zetnet.co.uk/mega.disczine/