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Re: More Voltage

> 	I was just wondering if anyone has attempted to use a 
> parallel charge, series discharge of caps in there Tesla coil.  It 
> seems possible to use a number of spark gaps, with increasing 
> breakdown voltages, to produce an increase in applied voltage.
> 
> 	---------------I------------------I------------------I------o
> 	  |     \             |     \            |    \   
> 	  |      \	      |      \           |     \
>   	-----     o        -----      o       -----     o
> 	-----      o       -----       o      -----      o
> 	  |          \        |         \        |         \
> 	  |           \       |          \       |          \
>             ---------I--------------------I-----------------I-----------o
> 
> 	If say, we used a 5kv input, then the first gap could be set to 
> fire at 5kv, the second at 10kv, the third at 15kv, and the final gap, or 
> traditional spark gat set to 20kv.  Would this not appear t
 at we 
> input 20kv and not 5kv.  It seems logical, but has any one tried it?

This is known as a Marx generator and can be used to produce very 
high voltage DC pulses (I saw one reference for an 80-stage generator 
where the final output could be as high as 5MV using a 35kV input).  

NOTE: There should also be some inductors (shown in the above 
drawing as I's) to prevent the shorting of the capacitors at the beginning 
of the pulse discharge.

There are two ways to trigger the output.  First, all gaps can be set for 
the same breakdown voltage (which exceeds the charging voltage) and 
the first gap can be electronically triggered.  Alternatively, all the gaps 
except the first can be set for the same breakdown voltage (again which 
would be higher than the charging voltage) and the first gap would be 
set for a discharge voltage slightly lower than the charging voltage so 
that breakdown occurrs spontaneously when the capacitors are charged 
to a high enough voltage.  Regardless of the trigger mechanism, when 
the first gap fires, the high voltage would propagate down the line and 
trigger the rest of the gaps in turn.

I don't know if this has been used in a Tesla coil, but you could get very 
high voltage, probably relatively low rep-rate DC pulses from this 
setup.


Steven Roys (sroys-at-radiology.ab.umd.edu)