Sorry Gary for the missunderstanding,I did not mean "no center ground" , I meant without that "center protection system" Proper name??, that makes a NST unsuitable for us, that has to be amputated ..
Kind regards, Fritz----- Original Message ----- From: "Lau, Gary" <Gary.Lau@xxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx> Sent: Monday, June 01, 2009 8:43 PM Subject: RE: [TCML] NST Purchase Hi Fritz,While it would be nice not to have the secondary midpoint tied to ground, there's a very good reason that this is done. It's much easier and economical to have two secondary coils insulated to 7.5kV from case ground, than to have a single coil (or two tied in series) that are insulated to 15kV.
A compromise might be if the NST were designed with the inner lead of each of the two secondaries _moderately_ insulated from the core, to an external connection that we would connect to RF ground. This would allow the user to tie the case to mains ground, and to tie the secondary midpoint to a separate RF ground. It would probably be a good practice to connect a HV-rated choke between the RF and case grounds as a safety mechanism, in case the RF ground connection was broken.
However, my suspicion is that any NST manufacturer with assets worth protecting is not going to build a small quantity of non-standard product that does not meet existing safety requirements. Fun to dream though!
Regards, Gary Lau MA, USA
-----Original Message----- From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf Of fritz@xxxxxxxxxxxxxx Sent: Monday, June 01, 2009 1:17 PM To: Tesla Coil Mailing List Subject: [TCML] NST Purchase Dear all,Woud it probably be possible to place a c o m m o n order for 20? , 30? ,40? n e w robust NST`s ? 15/60 , modern internal design (good modern technology isolation) , Ordering from a reputated manufacturer , who is willing to run a small "side serie" , specs to our requirements : without the center ground protection system , Franceformer ?Personally I feel, good, new material (NST) is a advantage over old , ofunknewn "history" from breakjard ... Perhaps someone who speaks English, coud contact manufacturers , ask if possible to run a special small serie , what price, what minimum number to be ordered , what delivery time , then we coud perhaps collect orders , find out how many of us are interested and willing to pay the price, paying a deposit with theyr order , shipping - save packing had to be organised . Yes it is work ... Or someone who deals professionally , sells caps , secondaries , toroides and other stuff for us coilers coud do it , on a fair profitbase ?I am not too lazy to do - investigate this , but my handicap is not speakingproper English and beeing to far away (Switzerland) . Also I have no idea how many we are, if most of us are just happy with searching around for old, long time used NST`s , with uncertain internal condition ...? I woud be happy to order 2 new ones . Kind regards to all "masters of the long sparks" ... , Fritz Egli _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla
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