Re: Sync vs. async - was Re: [TCML] 3 phase sync.

[bturner@xxxxxxxx]

Hmmmm. More tinkering.

200KHz = 0.000005 sec per cycle. 0.32mSec / .005 = 64 cycles of
oscillation (burst duration). Question then is how FAST the secondary
oscillations peak (ring up). Loosely coupled takes more cycles?? The Corum
Brothers pointed out that the gap dwell time also must factor in the
coupling factor - indeed, tightly coupled systems peak better with very
short dwell times. Bang it FAST (and) HARD! So, by having short dwell,
tight coupling AND a high BPS, you get maximum ENERGY transfer (not
necessarily longer sparks.)

It's possible then that my gap breaks just a bit after ring-up decay in
the secondary.

The Corum paper points out several stages - first is to find critical
coupling. THEN determine the number of primary oscillations necessary to
bring the secondary to it's peak resonance rise. (Impulse equations) THEN
adjust gap dwell time to allow for ONLY that time of primary burst rate.
BPS rate then based on the limits of the input power source. (Hence either
a HUGE transformer, or smaller Cp to reduce saturation possibility.)

Also, if the secondary's energy is dumped at maximum oscillation, not a
whole lot left to collapse back into the primary. Which means the coupling
then can be REALLY tight... Either via discharge or impedance-matched
free-resonant 'extra' coil... I kinda like the heavy discharges myself. 
:-)

Highest POWER means very tight coupling. Highest VOLTAGE means very loose
coupling, or tight coupling with an extra coil.

Aren't Tesla coils fun???


- b




> Gary -
>
> The classic quench gap (multiple stacks of discs on top of each other)
> does extinguish after the first loss of primary oscillation and takes a
> higher level of re-ionizing voltage. Rotary gaps can be quenched via air
> blast, etc. I am using 1/4" pure tungsten rods for the fixed electrodes,
> and 3/16" pure tungsten for the rotary ones with a decent air blast into
> the electrode proximity area. I have them on a 10" diameter rotating at
> 3600 rpm. Approximately 158 feet per section of velocity. Gap proximity is
> approximately 1/4" + 2(3/16") = .625" of angular vicinity. At 158 ft/sec
> that is roughly 0.32mSec.
>
> Granted, I am quite sure it's not quenching at the first notch, but also
> fast enough to keep a major portion of the secondary energy 'trapped' (3-4
> ring cycles). The Corum Brothers did a bit of a dissertation on this way
> back in the early 1990's. Matching dwell time to the first 'notch'
> radically increases energy transfer. This CAN be mechanically realized
> with either incredibly large diameters or with the use of two
> counter-rotating sychronized gap rotors (toothed belt-drive) which will
> cut the dwell in half for a given RPM. (A LOT safer...!)
>
> Ooops, I confess to a suddenly noticed typo - my Cp is 0.06uF, NOT 0.6uF.
> So, with a 4-turn flat primary with a mean diameter of 18" has a very
> small Lp since the system resonates at approximately 200KHz with a 5"x20"
> toroid. Granted, with a lower Fr (higher Ls and Cs - say, an 8"x30" toroid
> -) I may gain an extra 12-18" of discharge length, keeping the same
> primary and gap arrangement. However, the system runs like a freight train
> (and damn near as tough!) and I can't complain about the intensity of the
> discharges as it stands...
>
> OK, yeah the 100' discharges are likely mythical. However, the power
> levels Tesla generated were nothing to sneeze at.
>
>
> - b
>
>
>
>> Hi Brent,
>>
>> A couple of comments on your post, interspersed below:
>>
>> On Tue, Feb 7, 2012 at 2:50 PM, <bturner@xxxxxxxx> wrote:
>>
>>> Higher break rates don't equate into longer discharge lengths. Given
>>> that
>>> the primary circuit isn't swamping out the transformer (saturating) a
>>> higher BPS results in simply more bangs per second from the secondary,
>>> ie;
>>> transfer of greater energy OVER TIME.
>>>
>>> In my 'medium-size' coil system, I have 0.6uF and originally ran at
>>> 120BPS. Got 6 foot discharges that nicely wandered around. I upped the
>>> BPS
>>> to 240 and the discharges did not increase in length, but became FAR
>>> more
>>> energetic.
>>>
>>> Most recently, a gap re-design produced 600BPS(!). Of course the power
>>> draw (or suck??) went up, but the discharges, though still only about 6
>>> feet in length, are FAT, NOISY and HOT. White-hot! And my transformer
>>> is
>>> only 1:100 ratio, meaning 12Kv output voltage.
>>>
>>> If we step back and think about it for a moment, that's why Tesla had
>>> such
>>> a high BPS in the Magnifying Transmitter - High Cp and low Hp equals
>>> FAST
>>> field build and collapse which couples a lot more energy, which makes
>>> sense as the 'secondary' was merely a high-current signal source for
>>> the
>>> extra coil.
>>>
>>> It's also important to note that the gap dwell time plays a BIG role in
>>> energy transfer as well. Long dwell in low Z systems is detrimental due
>>> to
>>> a portion of the magnetic field being lost BACK through the gap.
>>> Ideally,
>>> dwell is such that the gap duration *JUST* cuts off when the resonant
>>> rise
>>> in the secondary peaks. Since my system has only 4 turns in the
>>> primary,
>>> and approximately 240 turns in the secondary, it is a relatively high
>>> Q,
>>> low Z system. So a short gap time and high BPS then allow a helluva lot
>>> of
>>> energy to be coupled to the secondary.
>>>
>>> I was under the impression that gap dwell time had little to do with
>> primary/secondary dynamics and coil performance, except for situations
>> when
>> the dwell is so long and Cp is so small that multiple bangs occur per
>> presentation.  But since your Cp is a beefy 0.6uF, that shouldn't
>> require
>> a
>> short dwell time to prevent re-ignition.
>>
>> I'm also unclear on what you mean by "a portion of the magnetic field
>> being
>> lost BACK through the gap".  It sounds like you're describing secondary
>> energy transferring back to the primary tank following the first (or
>> subsequent) notch(es), but I'm not sure that one can alter when a gap
>> quenches simply by minimizing RSG dwell time.  Are you suggesting that
>> you
>> can force first-notch quench just by having a suitably short dwell time?
>>
>>
>>> Crude math approximation revealed approximately 18 joules(!) of peak
>>> discharge energy occurring at 600 times per second. Given the uS rate
>>> of
>>> secondary discharge duration, that worked out to something like 18MW(!)
>>> of
>>> peak secondary impulse energy. (And I sit on top of THAT...)
>>>
>>> No wonder Tesla was able to coax 100+ foot discharges off the top of
>>> the
>>> 'Transmitter'. (Also no wonder why if I'm not careful, a power-arc will
>>> literally throw me off the table.)
>>>
>>
>> Now now, we've been down this road before - let's stop propagating this
>> myth.  I thought we were all in agreement that the oft-cited 100+ foot
>> figure was not at all based in fact.
>>
>> Regards, Gary Lau
>> MA, USA
>>
>>
>>> - brent
>>>
>>> <snip>
>>>
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