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ISO longer sparks at less i
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From: FutureT-at-aol-dot-com [SMTP:FutureT-at-aol-dot-com]
Sent: Thursday, June 18, 1998 10:15 AM
To: tesla-at-pupman-dot-com
Subject: Re: ISO longer sparks at less i
Dale,
I've used this pulsed burst method for increasing the spark length
using a fixed input power, and it does work as expected. I've used
AC and also DC power supplies. I used two rotary gaps in series
to create the proper pulsing effect. One was a normal rotary, and
the other was slow turning *enabling* rotary. I found that at least
24 gap firings are needed during each pulse to give a reasonable
spark length. However, I didn't do very many experiments with
varying the break rate, etc. If I remember correctly, I used both
360 and 480BPS for the normal rotary, and about 4BPS for the
enabling rotary. I obtained about a 54" spark using about 400 watts
or so, but it was a little hard to measure the current with a normal
meter due to the pulsing. The coil made an unusual sound, and
the bright pulsing flashes were unique. I've posted the complete
details for the system on this list in the past (I think), so they should be
available in the archives. I wrote an article about my system which
was published in the TCBA Newsletter, vol 15, #4 (Oct, 1996). The
article was titled: "The DC Disruptive Pulsed Compound Storage Tesla
Coil."
It was an interesting project, but it had two weaknesses in my opinion;
the intermittent pulsing tended to prevent super-long spark streamer
growth, and the need for a large number of firings per pulse demanded
large intervals between pulses, which made the spark appear quite
visibly pulsed to the observer, (this may or may not be a disadvantage).
John Freau
--------------------------------
> ISO = In Search Of
> MultiTap_MultiGap, Multi<>Cap_Single_Tap, Multi=Cap_Multi<>Tap
> Progressive_Tap_MultiGap, Progressive_Tap_Gap
> To list:
> I am pondering methods to achieve longer spark discharges (SD) while
reducing
> required input power. My theory is that a long SD's may be achieved by
> providing properly timed multiple close spaced primary energy dumps with a
> delay before the next burst. The nature of the SD's will change from
hundreds
> of widely varying in length to fewer, each of a longer length thus requiring
less
> overall average input power to achieve the fewer but max length SD's.
> (rates: DC=infinitely variable <1 to >20?, ac=50/60 unipol or 100/120
bipol)
> For the AC input case it would be nice for 2*120=2.4KW to provide SD's of 6'
to
> up to 20' maybe more. I think this can be achieved. The trade off should be
the
> number of cap dumps per second must be redistributed (bunched) with the
> overall number reduced. In the RSG case increasing the break rate increases
> SD length provided there is adequate input power available. At 480 bps / 60
Hz
> = 8 SD's per cycle (4 in pos cycle 4 in neg cycle) or one every 16.67/8 =
> 2.08ms which represents the time the Pri Cap has to charge before it is
> switched to the Pri inductor. The challenge is to come up with an approach
that
> allows multiple closely spaced switched charges (2 for now more later) in
~10us
> up to ~1ms bursts occuring only once (all pos or all neg) or twice per cycle
> (oneof ea polarity to see if bipolarity is a factor in producing longer
SD's) -
> separatedby 8.3ms or 16.7ms. The RSG implementation could be an inner row
> for the extra cap positioned to align just after the outer row breaks.
> A differential concentric adjustment scheme would be desirable.
> The DC input case would allow more flexibility in time between bursts
allowing
> further reduction of input power vs SD length as it needn't keep step with
the
> varying sine wave. Its implementation could consist of vacuum switches and
> timed electronic activation. The DC case could be set up for unipolarity or
> bipolarity. DC should permit very long SD's at very low average input power
> since the time between bursts is unconstrained.
> The general approach is to use two (more later) primary charge sources to
allow
> two (or more) close spaced primary energy dumps. This requires two charge
> sources (NST's), two Discharge Caps of equal value and two (or more) switch
> paths to two spaced taps. The first dump at "before streamer" resonance is
> followed by a second at a little higher inductance tap (further along the
turn
> = lower Fres) to account for a slightly larger Sec top capacitance streamer
> which slightly lowers Fres, corrected with a little more inductance.
> The second streamer will hopefullly build onto and enlarge the first
streamer.
> Alternately two slightly different capacitances and two (or more) switch
paths
> to the same tap could affect the same result.
> Unknown for either is if it is possible to switch multiple dumps of high
energy
> close together without one triggering the other. Then again this coupled
> triggering might be usable and desirable in the quest for adding subsequent
> charge to the existing streamer.
> Has anyone tried this ? likely to ? comments ? Dale, Redondo Beach, Calif
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