Re: [Fwd: Spark gap not firing]

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-uswest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net>
> 
> Ralph -
> 
> I have built and tested several TC's with the capacitor across the NST and
> never lost a NST. I always used a protective spark gap across the NST output
> as I show in my books. These protective gaps would operate once in awhile
> during tests so a high voltage was never across the NST output. I do not
> believe Terry's NST tests prove that the cap across the NST is more of a
> risk than the gap across the NST.
> 
> Terry's test setup does show current spikes in the test circuit but high
> voltage is what damages the windings and the curves  show only normal
> voltages across the NST output. According to the List there have been many
> NSTs destroyed that had the operating gap across the output. The TC primary
> regardless of where the gap is located can have destructive voltages created
> during operation and a protective gap across the output will keep these
> voltages from shorting the windings.
> 
> John Couture

	John's assessment seems very reasonable to me; certainly transformers
can be shorted by over-volting by opening the gap too far in a quest for
bigger sparks.  Does anyone have ANY data which substantiates failure of
a transformer  due to impressed RF voltage within its design ratings? 
With the capacitor connected across the transformer there will be no
significant higher-frequency voltages across it.  With the spark gap
connected across the transformer (a configuration I prefer, by the way)
at the instant of firing there are some pretty rapid steps in the
voltage.

Ed