High voltage test setup with NST

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PazHeping
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Joined: Fri Aug 14, 2020 2:26 am
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High voltage test setup with NST

Post by PazHeping »

8A695A17-143D-44D8-8458-5ADAB630E742.jpeg
Hi everyone,

My first post in a bit. Doing an attic renovation and had to focus on that for a few weeks.

So my first foray into this project was met with a lot of set backs and I found myself suffering from what the FAQs warned; HV power supply troubles. The above picture is my attempt to see if the neon sign power supply I got from Amazon was worth keeping away from the garbage. Since I don’t have an HV probe I came up with the simplest circuit that I could test with continuity and visual correctness before powering on. So, NST into full wave rectifier and a Jacob's ladder. After getting it all put together I powered it up and got a nice solid, non sparking, deep violet purple corona. My wire separation was in the 1 to 2 cm range and although I have read Richard’s paper on NSTs I think that I was getting a solid 10000V. Transformer says it’s 30mA so was it a 300 watt corona??? Idk but I was glad to get expected results.

My question now is this,,,can I make 3 or 4 of these and wire the HVDC from the rectifier in series to get 30kv? Seems to me it’s workable but was wondering if anyone has any input on going this direction? This transformer was only 40bux and the modularity of a few of these wired in series appeals to me if in fact it’s a reasonable configuration.

Thanks in advance,
Paz
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The less you bet, the more you lose when you win.
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Richard Hull
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Re: High voltage test setup with NST

Post by Richard Hull »

No, you cannot chain these arrangements in series. Remember, you must be able to retain a hard ground on the positive output. You will always have to worry about backwards paths for all electrical efforts with rectifiers to ground and insulation issues.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
PazHeping
Posts: 14
Joined: Fri Aug 14, 2020 2:26 am
Real name: Paz_Heping

Re: High voltage test setup with NST

Post by PazHeping »

Richard,
Thanks for the response. Perhaps you can clarify something I’m missing. When considering diode leakage, wouldn’t these be equivalent circuits?
B527B47D-C1C8-4D6E-B295-08123BD391C2.jpeg
Thanks, and sorry if I’m off base with something but I’ve been mulling this over a while.
Paz
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The less you bet, the more you lose when you win.
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Richard Hull
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Joined: Fri Jun 15, 2001 9:44 am
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Re: High voltage test setup with NST

Post by Richard Hull »

Again all neon transformers are physically center tap grounded to the case and should be grounded for safety. Thus, a simple bridge circuit, by itself, will not function as envisioned unless you do not ground the transformer case. this can lead to any number of issues like a electrically deadly case against ground. Your assumption about 10kv @30 ma is wrong in arc conditions the output voltage should be less than 1,000 volts
@ 30ma.

You need to read the text file in the files section about neon transformers never supply full current and full voltage. Much to learn through reading.

Finally, a 10 kv transformer that is full wave rectified should output 14,000 volts DC, no load! Math sez so....

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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