[Home][2015 Index] Re: [TCML] Dual identical FRANCE neon sign transformers (15000v 60mA each) in parallel [Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] Dual identical FRANCE neon sign transformers (15000v 60mA each) in parallel



I think that the very first thing you should do is spend 5 bucks on the
tesla coil design software called TeslaMap. It's invaluable and will
answer so many of your questions.


On 15-02-21 06:26 AM, Timothy Gilmore wrote:
> Gary,
>
> Sounds like a pretty scary adventure veering off from the plans I have
> which indicate simple things such as just adding more capacitance. I think
> what I will do first is get a working single NST tesla coil first
> (15kv/60mA) and using the 2nd NST as a backup incase the first ever gets
> fried. If it looks like the design is stable than perhaps later on I will
> take on a 2 NST new design. Its been 35 years since I built my first and so
> much great development has happened and new ideas learned by the smart
> people here and other places in the Tesla Coil world. Thanks again for your
> insight and the others here that make this such a fun hobby.
>
> Tim
>
> On Fri, Feb 20, 2015 at 8:02 PM, Gary Lau <glau1024@xxxxxxxxx> wrote:
>
>> The only reason to have transformers be identical is a matter of
>> aesthetics.  As long as the output voltage is remotely similar, one can mix
>> France, Jefferson, whatever, flavors of NST's, if the phasing is correct,
>> and you'll know immediately if it's wrong.  It's _nice_ to have them
>> identical but functionally unnecessary.
>>
>>> There would be a lot more changes than just caps and gaps.
>> I would like to amplify the above point.  Assuming you want to do
>> everything needed to extract the maximum arc length from the additional
>> power at your disposal, repeat over and over - Bigger is Better.  You'll
>> want a larger top load, and you'll want a taller secondary to space the top
>> load farther from the primary to avoid strikes to it.  The larger top load
>> and secondary will require a significantly larger primary, not just another
>> couple of turns.  I ended up building a 2-layer primary to keep
>> the dimensions sane.  Higher inductances and lower frequencies are all
>> good!
>>
>> Also, a 15/120 power supply is probably going to push the limits of what a
>> static gap can handle.  You didn't mention what you're planning for a gap
>> but you might wish to consider a rotary. I highly recommend the propeller
>> gap configuration - http://www.laushaus.com/tesla/sync_gap.htm   If you're
>> thinking about a synchronous rotary, the capacitor size needs to be much
>> higher than for a static gap, and will require comparably more primary
>> inductance.
>>
>> And, a 15/120 power supply is going to pull a LOT of juice from the wall -
>> you'll want to make sure you have an adequate PFC capacitor to minimize
>> current draw.  My single 15/60 pulls in excess of 20A with a sync rotary
>> and 240uF of PFC caps.
>>
>> Bottom line - you should plan from day 1 what the final configuration is
>> going to be - you'll not be able to go back and forth with 1 or 2 NST's.
>>
>> Regards, Gary Lau
>> MA, USA
>>
>>
>>
>>
>>
>> On Fri, Feb 20, 2015 at 1:32 PM, Timothy Gilmore <tdg8934@xxxxxxxxx>
>> wrote:
>>
>>> Great videos on Phasing (both parts 1 and 2). I will watch those again
>> when
>>> ready to set up.
>>>
>>> On Fri, Feb 20, 2015 at 9:36 AM, John Paul Grippa <pupman@xxxxxxxxxxxx>
>>> wrote:
>>>
>>>> There is a great video from the Geek Group on YouTube that explains how
>>>> this works extremely well.  It will also give some good tips on how to
>>>> ensure proper phasing.  Check it out!
>>>> https://www.youtube.com/watch?v=KSlQjw9OPG4
>>>>
>>>>
>>>>> Date: Fri, 20 Feb 2015 08:26:17 -0600
>>>>> From: tdg8934@xxxxxxxxx
>>>>> To: tesla@xxxxxxxxxx
>>>>> Subject: [TCML] Dual identical FRANCE neon sign transformers (15000v
>>>> 60mA     each) in parallel
>>>>> I currently have a France NST at 15kv 60mA and built a nice jacobs
>>> ladder
>>>>> with it. Yesterday on eBay I found what looks to be identical model
>> NST
>>>> for
>>>>> a good price (no GFI). From what I have read about NST phasing,
>> having
>>>>> identical NSTs don't require testing the HV outputs and I should be
>>> able
>>>> to
>>>>> connect them up in parallel identically using the same sides. What a
>>>> jacobs
>>>>> ladder at 120mA would be! Anyway I'm assuming that I should start
>>>> building
>>>>> my tesla coil with 1 NST and when it works add the next NST in
>> parallel
>>>> and
>>>>> double the capacitors and change the tap on the primary. Does this
>>> sound
>>>>> like all I would need to do?
>>>>>
>>>>> Thanks - Tim
>>>>> _______________________________________________
>>>>> Tesla mailing list
>>>>> Tesla@xxxxxxxxxx
>>>>> http://www.pupman.com/mailman/listinfo/tesla
>>>> _______________________________________________
>>>> Tesla mailing list
>>>> Tesla@xxxxxxxxxx
>>>> http://www.pupman.com/mailman/listinfo/tesla
>>>>
>>> _______________________________________________
>>> Tesla mailing list
>>> Tesla@xxxxxxxxxx
>>> http://www.pupman.com/mailman/listinfo/tesla
>>>
>> _______________________________________________
>> Tesla mailing list
>> Tesla@xxxxxxxxxx
>> http://www.pupman.com/mailman/listinfo/tesla
>>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla