If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #3806
Joined: Sat Apr 02 2011, 09:20PM
Location: France
Posts: 259
Hi all,
I'm planning to buy a NST that could suit as many as possible HV experiments.
I found a french supplier who sells good "old style" NST's (Metal case, no protection) in the range of 1KV to 10KV and 10mA to 100mA.
Without any price consideration, shall I better buy the biggest (1KW) one ?
Using a Variac, will it suits esperiments that require lower Volt / Amp ?
Sorry to bother you with all these n00b questions, but some Pro's advices are really helpull when starting with this great hobby , thanks in advance for your kind help
Registered Member #3610
Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506
The biggest one you can afford will probably be the most versatile. I would suggest looking for a used one first though, a single new one costs more than all the used NSTs I've ever bought combined.
Registered Member #3610
Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506
Yeah try to drop by when they don't look too busy, tell them you build Tesla coils as a hobby and are looking to buy a few used transformers. Chances are they'll have something and won't ask much for it.
Registered Member #2099
Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1716
PhilGood wrote ... ... in the range of 1KV to 10KV and 10mA to 100mA. Without any price consideration, shall I better buy the biggest (1KW) one ?
The nameplates of NST's are unique, in giving the open circuit voltage and the short circuit current. Normal steady state operation is approximately the SC current at a small fraction of OC voltage.
So "10 kV 100 mA" on a NST is not even close to 1 kW or 1 kVA. The maximum power you can get is less than half of the V_OC * I_SC product. I wonder if this is in our HV Wiki? There may be exceptions with resonant loads, which I'm not familiar with, and are probably hard on the NST.
I'm shocked (figuratively) that NST's are made with a 100 mA rating. That's more dangerous than 30 mA, and invites mandatory ground fault interrupters not just for the risk of an exposed connection arcing to ground and starting a fire.
Registered Member #3806
Joined: Sat Apr 02 2011, 09:20PM
Location: France
Posts: 259
IamSmooth wrote ...
There are always several on Ebay
I have the Franceformer 15kv/60ma, but the 30ma model is fine.
Unfortunately most NST's on eBay do not ship outside US, and are 120v 60Hz, I need 240v 50Hz (btw shipping would probly be lot more than the NST price itself)
So if I'm unlucky with local neon sign shops, I'll have to buy a new one... :/
Klugesmith wrote ...
The nameplates of NST's are unique, in giving the open circuit voltage and the short circuit current. Normal steady state operation is approximately the SC current at a small fraction of OC voltage.
So "10 kV 100 mA" on a NST is not even close to 1 kW or 1 kVA. The maximum power you can get is less than half of the V_OC * I_SC product. I wonder if this is in our HV Wiki? There may be exceptions with resonant loads, which I'm not familiar with, and are probably hard on the NST.
Registered Member #3610
Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506
Klugesmith wrote ...
PhilGood wrote ... ... in the range of 1KV to 10KV and 10mA to 100mA. Without any price consideration, shall I better buy the biggest (1KW) one ?
The nameplates of NST's are unique, in giving the open circuit voltage and the short circuit current. Normal steady state operation is approximately the SC current at a small fraction of OC voltage.
So "10 kV 100 mA" on a NST is not even close to 1 kW or 1 kVA. The maximum power you can get is less than half of the V_OC * I_SC product. I wonder if this is in our HV Wiki? There may be exceptions with resonant loads, which I'm not familiar with, and are probably hard on the NST.
I'm shocked (figuratively) that NST's are made with a 100 mA rating. That's more dangerous than 30 mA, and invites mandatory ground fault interrupters not just for the risk of an exposed connection arcing to ground and starting a fire.
The big ones are rare, I've seen 60mA, and heard of 100mA and even 120mA but never actually seen one. Technically not neon, but cold cathode transformers for architectural lighting. They're made just like "neon" tubes but usually larger, up to an inch in diameter and use a white phosphor.
Registered Member #1408
Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679
To the best of my knowledge, the higher current (60ma+) are used in areas of substantial cold such as in the US Mid-West or East Coast. in areas of moderate climate they are tough to find since that current level is simply not needed. The only area where real unique "finds" occur in NST configurations are in places like Las Vegas or Atlantic City due to the unusually large signs and commensurate levels of gas. Some large Asian cities also has uniquely large neon signs and areas such as those would be a very likely spot to find outstanding examples. unfortunately ground fault /solid state configurations are the standard these days and the large manufacturers are really only making the older type to a special order level. A company in Thailand has been making some for Information Unlimited but the prices are very high.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
pls Need advice to buy appropriate NST
