Re: [TCML] Single-ended NST, wiring

[jhowson4@xxxxxxxxxxx]

Brian, I was unsure of how bad the primary/RF ground really is, as I have seen numerous people do this or similar over the years, so I went digging through the list archives to find an answer, it turns out DC Cox used to do just that; 

>From 2006 
"We always ground one of the HV bushings (either H1 or H2) to the main 220 volt ground. This then goes from the power supply over to the coil via standard 10 AWG THHN wire and when connecting to the spark gap, it also connects to the inside of the pri Tesla transformer copper tubing and also to the main RF ground. The base of Tesla coil sec also connects to the main RF ground. We then run a 2 ought fine stranded welding cable to our main bldg ref ground which is connected to 2 parallel external copper grounds outside. In our museum applications we always have them install a 2 ought welding cable from dual exterior bldg ground directly to the demo stage area where it terminates as the base of the Tesla sec coil, ie, main RF ground. Dr. Resonance" 


cheers, 
John "Jay" Howson IV 


"Why thank you, I will be happy to take those electrons off your hands." 

----- Original Message -----
From: "Brian Hall" <brianh4242@xxxxxxxxxxx> 
To: tesla@xxxxxxxxxx 
Sent: Monday, March 4, 2013 9:26:26 PM 
Subject: RE: [TCML] Single-ended NST, wiring 


One thing to be careful of in both those drawings linked to is the ground connection.In general two parts of a Tesla coil should be grounded: the secondary coil to a ground plane or earth ground, and the low voltage end of your HV transformer (the part that plugs into the 110/220 VAC wall socket). 
You do not want to ground the high voltage (and also high current) primary (tank) circuit - the part with the gap, the cap and the primary coil as shown in the second drawing - and as mistakenly shown in the first pic linked to, you most definitely do not want to have a physical wire connection between the primary and secondary coil. You may have seen a coil drawn like that with Tesla's name associated it, and such coils exists for example an auto ignition transformer - but those are sealed tight in plastic casings filled with oil. 
In the more traditional sense of a Tesla coil discussed here, power travels through the tank or primary circuit to the secondary circuit just by being near it without physically touching, through electromagnetic inductance. No physical connection between the primary and secondary coil is needed or desired an an air-core Tesla coil. 

---------------------------------- 

Brian Hall 




> From: pastor@xxxxxxxxxxxxxxxxx 
> To: tesla@xxxxxxxxxx 
> Subject: RE: [TCML] Single-ended NST, wiring 
> Date: Sat, 2 Mar 2013 16:51:25 -0600 
> 
> I've always used the "capacitor in series" configuration 
> for my SGTC's... works great. 
> 
> 
> > -----Original Message----- 
> > From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf Of Jacob Karlström 
> > Sent: March 02, 2013 2:08 PM 
> > To: tesla@xxxxxxxxxx 
> > Subject: [TCML] Single-ended NST, wiring 
> > 
> > Hello, 
> > 
> > The NST (4kV, 50mA) for my SGTC is a single end type with one of its 
> > secondary winding ends attached to the metal casing. I have seen schematics 
> > of other TCs with single-ended transformers, and they have all looked like 
> > this: http://www.physics.gla.ac.uk/~kskeldon/PubSci/images/tesla3.gif with 
> > the capacitor in parallel with the transformer and coil. However, I recall 
> > reading that a capacitor in parallel is not preferred in a TC using an NST. 
> > I am wondering if connecting the capacitor in series instead like this, 
> > http://imgur.com/JegqUiI, would work, or will there be any problems with 
> > the capacitor + ground? 
> > 
> > Regards, 
> > 
> > Jacob Karlström 
> > _______________________________________________ 
> > Tesla mailing list 
> > Tesla@xxxxxxxxxx 
> > http://www.pupman.com/mailman/listinfo/tesla 
> > 
> > 
> > ----- 
> > No virus found in this message. 
> > Checked by AVG - www.avg.com 
> > Version: 2013.0.2899 / Virus Database: 2641/6141 - Release Date: 03/01/13 
> 
> 
> _______________________________________________ 
> 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