# Re: OLTC update - A problem!

```Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi,

http://hometown.aol-dot-com/futuret/page5.html

It is:

Ques: How long will my sparks be for a given input power?

Ans: In a well designed TC, the spark length will follow the formula:

spark length (inches) = 1.7*sqrt input power (wallplug watts)

Cheers,

Terry

At 05:10 PM 8/29/2002 +0200, you wrote:
>
>
>Tesla list wrote:
>
>> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
><FutureT-at-aol-dot-com>
>>
>> In a message dated 8/28/02 10:24:06 PM Eastern Daylight Time,
>tesla-at-pupman-dot-com
>> writes:
>>
>> >
>> > With 286 watts in I should be able to get streamers of 28 inches according
>> > to John's formula.  Much more considering I am not burning power in a
spark
>> > gap.  But either the low frequency (I note that I am at the frequency of
>> > Greg Leyh's Electrum which seems to come in a little low for streamer
>> > length given the input power)
>
>Terry, where is John's formula? Probably I have it in some paper, but I'm
>not able
>to find it.
>
>Cheers
>
>
>>
>>
>> Terry,
>>
>> Congratulations on your results so far.  Regarding Greg's Electrum
>> coil, I seem to remember that it gave about the same spark length,
>> as the break-rate was increased within a certain range.  Near the
>> low end of the break-rate range, the coil was quite efficient.  I think
>> Greg said the coil gave almost the full spark length of 40 to 50 feet,
>> at 110 bps or so.  As he raised the breakrate, the sparks became
>> bushier and fuller, but not much longer.  I think it drew 40kW at
>> 110 bps or so, and gave maybe 38 foot sparks.  This easily
>> surpasses what my equation predicts.  This information is not
>> as Greg's website, and I may not have it 100% accurate, because
>> I gathered it from data in his various emails, but I think it's
>> close, and if I'm correct, it suggests that Greg's coil is capable
>> of very high efficiency at the lower break-rates.  Maybe Greg
>> will comment further.
>>
>> John
>

```