Re: The Best Pmimary Type Was: A few Q's from a beginner

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

Original poster: "torlin by way of Terry Fritz <twftesla-at-qwest-dot-net>" <torlin-at-ghostmail-dot-net>

 From the few pics I have seen of The Colorado Springs 
Lab, I believe Tesla himself was using a solenoidal 
primary.  ( I think that is the one where the windings are 
vertical | | instead of conical \  /  or /  \.  However, 
he had quite a bit more power available for his disposal. 
 

I personally used a solenoidal and an inversed cone \  / 
primary, and just naked eye observations, I thought the 
cone was a bit better where it counted, arc length.  

However, I didn't get into all the phase variations, and 
was using only a static SG, instead of the fancy rotary, 
phase matched, tungsten and whatever spark gap.  

I was building in my garage, for the fun, and my spark gap 
was a couple of lifters stolen from the local auto garage 
when they were repairing my engine.  Flat surface, about 
the size of a dime, and a couple of doorknob caps, and an 
old oil furnace transformer I stole from my dad when he 
changed to gas.  

Perhaps someone out there with the lab equipment and cash 
to back it up can build several different shapes of 
primary, and see what looks best, both in arc length, and 
all the neat lab tests that people seem to need.

On Sat, 30 Mar 2002 18:06:22 -0700
  "Tesla list" <tesla-at-pupman-dot-com> wrote:
>Original poster: "Barton B. Anderson by way of Terry 
>Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>
>
>Robert,
>
>I would say... the same thing John said. However, I 
>suspect your comments about
>primary types has to do with either some tests you have 
>run or models
>you've run?
>Kind of curious if the comments stem from a look at surge 
>impedances for
>primary
>types or maybe flux convergence to a typical solenoid 
>secondary? Obviously, I'm
>curious if you could elaborate a little more on the 
>subject.
>
>Take care,
>Bart
>
>Tesla list wrote:
>
>> Original poster: "by way of Terry Fritz 
>><twftesla-at-qwest-dot-net>"
><FutureT-at-aol-dot-com>
>>
>> In a message dated 3/30/02 2:29:00 PM Eastern Standard 
>>Time, tesla-at-pupman-dot-com
>> writes:
>>
>> Robert,
>>
>> I am not as confident as you are that the best form is a 
>>45 degree
>> form.  I also don't see anything difficult about 
>>building it.  I also
>> would not say that a flat primary has less efficiency. 
>> I also would
>> not say that a solenoid coil has the best coupling or 
>>power transfer.
>> I also would not say that solenoid coils have more 
>>racing sparks,
>> and arc over problems.  Any of the primary shapes can be 
>>easily
>> adjusted to give optimal coupling, and power transfer, 
>>without
>> arc-over or racing sparks.
>>
>> It's true that a solenoid coil can give the tightest 
>>coupling,
>> but tightest does not necessarily mean optimal.
>>
>> I've used a flat primary for a tube coil, and that 
>>worked fine too,
>> and was quite efficient.
>>
>> Certain shapes may have less inductance for a given wire 
>>length,
>> thereby increasing the losses, but the results on spark 
>>length
>> will probably not be noticeable.
>>
>> Cheers,
>> John
>>
>> >
>> > Brad: the costruction of the primary is a trade-off. 
>>The best form is a 45o
>> > cone slightly above the base of the secondary. This is 
>>hard to
>construct and
>> > mount. A flat primary has the least coupeling problems 
>>and is easy to
>> > construct, but has the least efficency. A solinoid 
>>primary has the best
>> > coupeling and power transfer, but the most arc over 
>>and running arc
>> > problems. It is the easiest to construct and most 
>>trouble. Tube TC
>coils use
>> > the solinoid coil primary because they nead the best 
>>coupeling to oscilate.
>> >