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Re: question: how can input ac phase be delayed

Perhaps if you current limited one transformer's current with a resistance,
and the other with and inductance, that would skew the phase to do what you
need.

A "pie in the sky" guess without any real experience though...

Cheers,

	Terry Fritz


At 11:53 AM 08/27/1999 -0400, you wrote:
>All,
>
>This is a question from Lou Balint regarding his TC magnifier project.
>
>Overview:    Lou built a magnifier that uses two power supplies, two 
>sync rotary gaps, two caps and primaries, and two secondaries, all
>driving one extra coil.  When both systems are fired up, the energy
>adds together and increases the spark length compared with the
>spark length when just one in running.  Lou demonstrated this TC
>at Ed Wingate's recent Super-Teslathon, unfortunately some of the
>spectators left before the final magnificent results were obtained.
>
>Purpose:   Lou reasons that in a giant system, such a method of 
>feeding the power from separate units might reduce the stress on 
>individual components, permiting a larger system to be built.
>
>Some details:    Since both gaps are 120 bps sync, they "want" to fire at
>the same time (to be at the peak).  However if they do fire at the same
>time, the RF tends to cancel due to imprecision in the rotary gaps, as
>would of course be expected.  As a result, it is necessary to set the
>gap phases so that one gap fires just after the other system rings down.
>This way they still fire near the peak, but the RF from one firing doesn't
>interfere with the RF from the other firing.  Since two firings are occuring
>per half cycle, this is really a 240 bps system, although the individual
>rotaries fire at 120 bps.  However unlike a standard 240 bps system, 
>here the two firings occur very close together in time, then almost a 
>full 120th of a second passes before the next "double firing".  
>
>The question:   To overcome the compromise of not firing at the
>absolute peaks, Lou would like to delay
>the incoming AC to one of the system's transformers so that the 
>systems could both be fired at their true peaks, while still preventing
>the bangs from occuring at the same time.  Can anyone suggest a
>method to delay the phase to one transformer?  I suppose some sort
>of series capacitor array could be used, but I'm not sure how well it
>would work, or exactly how it would be designed.  I seem to 
>remember reading about a system that used various stages of
>capacitive delay, but I forget the details.  A rotary converter
>would be another option, but might be inefficient.  Lou does not have
>access to 3 phase power.  Total input power range is 1kW to 2.5kW,
>in his present small demo set-up.
>
>Actually he could just adjust his ballast a little differently to one of
>the transformers (with a possible slight power factor penalty), and get
>some charging delay that way.  But still, he'd like to be able to get a
>larger range of delay to the input to compare differing amounts of 
>delay.
>
>Thanks,
>John Freau
>