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Re: Top Toroid

<<  el snippo -
 
 ><< It is still a question in my mind, whether slow break-rate, big bang, is
> > equal to fast break-rate, small bang.  There could be something going on
 >> with, for instance, the ion cloud that cause sparks to "grow" better with
>>one
>> scenario than with the other.  Something perhaps related to Richard Hull's
>> findings, that slow break rates cause more DC electrostatic charging, (and
> > maybe more spark length too)?  This whole break-rate question seems
 >> underexplored compared to many other TC aspects.
  
 >> Going back to non-sync gaps, I had an idea, which I don't know if I
posted
>> previously, that may suggest a scenario whereby non-sync gaps may enjoy an
>> unexpected boost in efficiency:  When a non-sync gap is run at a certain
>.> speed, and with a certain number of electrodes, it may give for instance
2
 >> breaks per half cycle for awhile, then 3 breaks per half cycle, for
awhile.
 >>  In this cycling is rapid enough, the eye will not really see the sparks
>> cycling (varying) in length, yet strong sparks will occur on a
>> regular,periodic basis, sparks that are perhaps longer than what would be
 .>> expected at the AVERAGE power level being used.  In other words, some
>>sparks
 >> are strong, some are weak, and the average power input is somewhere "in
>> between", so current is lower (than if all half cyles had 3 breaks), yet
we
>>  do occasionally get strong sparks, which is all we really care about.
 And
>>we
>>  can declare now declare this coil "more efficicient", from a "coiler's"
 >> viewpoint, but not of course from the true engineering viewpoint.
  
 >>>Flames, brickbats, and cat-calls are heartily welcomed. :^
   
 >> >- Bert H. --
    >>
  
 >> Guess I carried on enough for today!   Comments (of all types) welcomed!
  
>> John Freau
   >>
>I agree, this is a good topic for discussion.  My original rotary gap
> (asynchronous) was made from 3/8" polycarbonate, 10" in dia., with 8
> electrodes.  It is mounted on a 10,000 rpm series wound 1/2 hp motor (it's
>all I could find at the time - I know it is was too fast and I have never
> opened it up).  I had been running it at about 1/3 open on the variac.  I
am
>not sure how the rpm track with the voltage, but lets say this is about 3000
>rpm.  This would provide about 400 breaks per second.  Which is about what
> Richard Hull says is a good speed.  I noticed, however, that as I increased
>the rpm from there the sparks got longer (performance went up), more
>frequent, and the primary current went up.  It got to the point where the
> faster I ran it, the better it worked.  Once I got it up to what I thought
> was about 5,000 rpm, I was concerned that I was going to explode the rotor.
> So I built a new rotor, still 10" in dia, with 16 electrodes.  Now I ran it
>at about 3,000 rpm (a guess) and had 800 bps.  Still, as I increased the
>rotor speed, performance went up.  At 5,000 rpm this would be 1,333 bps.
 
 >This is all with my 6" coil running with the 5kva pole pig.  When my
> Condenser Products cap blew up, I was probably running somewhere around
1,000
> bps.  Maybe this is why I lost it, I know the pulses per second are a
> critical design factor with these.
 
>A question for Richard Hull, if 400 to 600 bps is what you see from
>experience as a good general number, why does this coil want higher and
>higher rpm?
 
>Comments anyone?
 
> Ed Sonderman
  >>

Ed,

In your coil, the pole transformer obviously provides enough current to fully
(or almost fully) charge the cap even at these higher break rates.  I have
also used break-rates around 1000 BPS. with good results.  Whether or not
fast break rates work well depends mostly on cap size and available current
from your transformer.  In your system, as your break rate increases, your
spark output increases, but your input power goes up more or less
proportionally.  You could obtain basically the same results by using a
slower break rate and a larger capacitor.

To gauge the true benefits of fast break versus slow break, it is necessary
to adjust the capacitor size, based on the break-rate to keep the input
current and power constant, and then seeing if the spark is longer or
shorter.  This kind of test is a measure of the other factors I mentioned in
my original post, such as benefits of longer cooling time for gaps versus
bigger bang, ion cloud distribution effects, etc, i.e. effects that may
affect efficiency.  My primary focus was, which scenario, fast break, small
bang (small cap!), or slow break, big bang (large cap!), would quench better
using a 12 point super series sync rotary gap with 6 offset gaps.

When the break rate becomes very high, the sparks sometimes become very
"frantic" and rapid in their "hunting" action, I wonder if this rapidity
limits spark length in a similar way to the way that the spark length is
limited in a tube coil if the energy builds up too quickly (if this is a true
cause??) there may be a parallel here?  It seems to be that the slow
"floating" sparks formed by low break rates may ultimately win the efficiency
prize.  More research is needed.

John Freau