Re: Low-voltage NST

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Bert Hickman by way of Terry Fritz <twftesla-at-qwest-dot-net>" <bert.hickman-at-aquila-dot-net>

Hi Antonio,

Small lower voltage NST's are often made with a single HV winding, neither
end of which is tied to ground. These typically (but not always) use open
"core and coil" construction. If you have an open core and coil transformer
you want to ground the "inner" lead (the end of the winding nearest the
core). If the unit is completely sealed, you may have little choice but to
simply pick one lead, ground it and take your chances. Certain new higher
power NST's may also have totally isolated secondaries as one way to meet
new UL safety standards.

-- Bert --
-- 
Bert Hickman
Stoneridge Engineering
Email:    bert.hickman-at-aquila-dot-net
Web Site: http://www.teslamania-dot-com

Tesla list wrote:
> 
> Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>
> 
> Hi:
> 
> I obtained recently a NST rated 5000 V x 30 mA. It has two high-voltage
> terminals with ceramic insulators, two input terminals for 115 V,
> and no ground connection at the case or anywhere. It produces a
> hot spark between wires attached to the terminals, with about 4 mm
> of length, and can power a Jacob's ladder that extends the spark
> to about 3 cm. Works best if I start with a distance where sparks
> can't jump, and start a spark with an insulated screwdriver.
> 
> I imagine that without a ground connection I can operate it with
> one of the output terminals grounded. Do someone have experience
> with similar NSTs?
> 
> Antonio Carlos M. de Queiroz