Hi Dennis,
A quick search through the Pupman archives will give you a much better
answer as to why an LTR cap is preferred for NST coils, than what I could
provide in a short post here. STR is often used for pole pig coils as
building an LTR coil for such large systems can become prohibitive.
For example, this post my David Rieben back last year explains it well:
https://www.pupman.com/listarchives/2006/Mar/msg00416.html
Cheers,
Ian
On 23/12/17, 7:56 am, "Tesla on behalf of dennis otmaskin"
<tesla-bounces@xxxxxxxxxx on behalf of dotmaskin@xxxxxxxxx> wrote:
>Thanks Ian for your reply! What you say is encouraging to hear. If you
>don't mind, I have one more question...
>
>Java TC indicates, for my 15/135 NST, that Resonant Cap Size would be
>0.0239uF. I understand that bad things happen when using resonant cap
>size. So I'm trying to decide on whether to use a 0.03uF cap or a .015uF.
>I've got one of each. The .03 cap is pretty close to the indicated .0358
>LTR Cap Size for a static gap. On the other hand if I plug the .015 cap
>into Java TC, it shows a dramatically greater rate of Breaks Per Second
>and
>possibly a few more inches of spark length. My question is is there any
>potential problem with resonant rise with the .015 cap. I.e., is the .015
>cap value far enough from the resonant cap size to be safe?
>
>Thanks again for your help, Dennis
>
>On Thu, Dec 21, 2017 at 11:55 PM, Ian McLean <austesla@xxxxxxxxxxxxxx>
>wrote:
>
>> Hi Dennis,
>>
>> If you have proper RCD¹s installed, it is unlikely you will trip a 15A
>> circuit with 18A at least for the sort of runs lengths you do on a Tesla
>> coil.
>>
>> I regularly ruin my tube coil at between 30A-40A from a wall socket.
>>The
>> RCD is only 20A, but it has never tripped even with a 2 minute run.
>>
>> Cheers,
>> Ian
>>
>> On 22/12/17, 2:40 pm, "Tesla on behalf of dennis otmaskin"
>> <tesla-bounces@xxxxxxxxxx on behalf of dotmaskin@xxxxxxxxx> wrote:
>>
>> >Hi I'm hoping someone from the list can offer advice some advice and
>> >suggestions. I am replacing the 15/60 NST on my current static gap
>>coil
>> >with a de-potted NST with some shunts removed so that it puts out
>>15000v @
>> >135mA.
>> >
>> >Running different designs on Javascript Coil Designer, I'm finding that
>> >the
>> >Effective Input Current (current draw?) runs over 18 rms amps. My wall
>> >outlets in the garage are all 15 amp. So if I'm understanding this
>> >correctly, it looks like I would be constantly tripping the circuit
>> >breaker
>> >when running the coil at full variac voltage. I've run different cap
>> >sizes
>> >through Java TC but cant seem to get around the 18 amp draw.
>> >
>> >To get the current draw to just below 15 amps, I would have to dial the
>> >variac down to 106 volts which would reduce the spark length
>> >substantially. I'm thinking that I am pretty much stuck with a systems
>> >that is limited to 106 volt input. Do you think this is the case? I'm
>> >hoping that I don't have to rewire my garage outlets for 20 amps just
>>for
>> >my coil. Any suggestions would be most appreciated.
>> >
>> >Thanks, Dennis
>> >_______________________________________________
>> >Tesla mailing list
>> >Tesla@xxxxxxxxxxxxxxxxxx
>> >https://www.pupman.com/mailman/listinfo/tesla
>>
>>
>> _______________________________________________
>> Tesla mailing list
>> Tesla@xxxxxxxxxxxxxxxxxx
>> https://www.pupman.com/mailman/listinfo/tesla
>>
>_______________________________________________
>Tesla mailing list
>Tesla@xxxxxxxxxxxxxxxxxx
>https://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxxxxxx
https://www.pupman.com/mailman/listinfo/tesla