Re: equidrive vs. non-equidrive

Subject:  Re: equidrive vs. non-equidrive
  Date:   Wed, 23 Apr 1997 23:45:18 -0400 (EDT)
  From:   richard hull <rhull-at-richmond.infi-dot-net>
    To:   Tesla List <tesla-at-pupman-dot-com>

At 11:06 PM 4/21/97 -0500, you wrote:
>Subject:      Re: equidrive vs. non-equidrive
>       Date:  Tue, 22 Apr 1997 07:51:27 +1200
>       From:  "Malcolm Watts" <MALCOLM-at-directorate.wnp.ac.nz>
>Organization: Wellington Polytechnic, NZ
>         To:  tesla-at-pupman-dot-com
>Hi Richard,
>             I'm delighted to see this post....
>> >All,
>> >
>> >I've done direct comparisons of the equidrive and single leg cap
>> >arrangements
>> >and found absolutely no difference either way.  This was in a small neon
>> >TC
>> >which gave about a 28" spark.  I haven't made comparisons at any other
>> >power
>> >levels.
>> >
>> >Towards optimal coiling,
>> >
>> >John Freau
>> >
>> >
>> All,
>> John is absolutely correct.  I really don't know how some might come to
>> think a positive electrical difference would be noted.  We have used the
>> "Equidrive" circuit in all our magnifiers only because the stress is
>> moved
>> out to two capacitors (twice as expensive).  Lotsa' stress in magnifiers
>> that the old two coilers never see! 
>>  The only observed advantage of the equidrive is the distribution of
>> heat
>> and electrical voltage stressed out over two units instead of one. 
>> Since we
>> have run this system we have never lost a capacitor.  That's a big
>> enough
>> advantage for me!
>> Capacitance is capacitance, no matter where it is in a tesla circuit.
>> Richard Hull, TCBOR
>I have always thought so too despite some people claiming it made a 
>difference. I was never able to see how or why it should.
>Malcolm, all.

The extra expense of the equidrive circuit is just one disadvantage.
Another is the lethality of the circuit due to one cap remaining charged
most of the time after shutdown.  Also, the extra wiring adds to off
inductance in the primary tank. For the magnifier builder, the above
disadvantages must be weighed against the rather cool running nature of
system and distribution of the shock of high coupled systems about more
circuit elements. 

For me, there was never a question.  The equidrive won out.  I didn't
like I needed to hammer the NWL super caps into an early grave.  Also,
high tank voltages are much easier to handle with series, equidrive
The key is to keep the primary L very high and then the percentage of
off axis inductance to flux coupled elements is quite small.

Richard Hull, TCBOR