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Dragon64

Sat Apr 12 2008, 02:17AM

Registered Member #1438 Joined: Sat Apr 12 2008, 12:57AM
Location: Canada
Posts: 218

Hey, I was browsing through the website whenI stumbled across this unique website. I Love HV and signed up right away.

Yesturday, I was working on my MOT and felt that I needed a Green Thumb's Up from the HV expert's out there before I connect my MOT to the 120 VAC.

My MOT is not ballasted to anything and im using the Microwave capacitor to limit the current the MOT draws out. Here are some schematic's and picture. If there is a problem, please let me know so that I wont kill myself when I hook it up to the 120 VAC.

[Edit: Maximum 400 pixels]

Arcstarter

Sat Apr 12 2008, 03:08AM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

First of all the ac does not have a positive or negative,it has a hot(or live) and ground. Second you do not use the filament winding(the thick wire with few turns). And the ground is actually the metal core. And the high voltage will not jump that gap. It will take like 20kv or more to jump it.

northern_lightning

Sat Apr 12 2008, 03:21AM

Registered Member #1348 Joined: Sun Feb 24 2008, 01:48AM
Location: Michigan's Upper Peninsula
Posts: 22

you probably don't want to use a wooden board. wood can be quite conductive with high voltages. be careful--MOTs might be readily available but they can also be deadly! perhaps a flyback-based project would be a better intro?

welcome to the forum

Dragon64

Sat Apr 12 2008, 03:27AM

Registered Member #1438 Joined: Sat Apr 12 2008, 12:57AM
Location: Canada
Posts: 218

I just redone my curcit so that the core will be my ground. Also I hooked up the HV end (Which would be the red HV tape stuck to it)

I purposly put the electrode far apart because I dont want the arcing to be close to the MOT.

I also decided to get rid of the capacitor. So now should I plug it in and let the HV wire touch the core?

northern_lightning wrote ...

you probably don't want to use a wooden board. wood can be quite conductive with high voltages. be careful--MOTs might be readily available but they can also be deadly! perhaps a flyback-based project would be a better intro?

welcome to the forum

Thanks :)

Well I've played around with my flyback running of my oscillator for too long and I also need to make a power source for my upcoming Tesla Coil. NST is to costly in my city.

[Edit: Double post]

Myke

Sat Apr 12 2008, 03:46AM

Registered Member #540 Joined: Mon Feb 19 2007, 07:49PM
Location: MIT
Posts: 969

A single MOT isn't the best thing for building a tesla coil because the voltage is relatively low and high current.
If the current it too high then you might have trouble quenching the arc.

Is this right? (I've never built a tesla coil before)

Dragon64

Sat Apr 12 2008, 03:56AM

Registered Member #1438 Joined: Sat Apr 12 2008, 12:57AM
Location: Canada
Posts: 218

Myke wrote ...

A single MOT isn't the best thing for building a tesla coil because the voltage is relatively low and high current.
If the current it too high then you might have trouble quenching the arc.

Is this right? (I've never built a tesla coil before)

Maybe I should get a NST.

How much do you guys pay for one?

Andyman

Sat Apr 12 2008, 05:32AM

Registered Member #1083 Joined: Mon Oct 29 2007, 06:16PM
Location: Upland, California
Posts: 256

If you get lucky, you can get them for under $30. Call your local neon sign shop and see if you can take the "failed" units off of their hands. Often, there is nothing actually wrong with them.
Look here

Be careful, don't buy any transformer that has secondary ground fault protection built in. Of course, there are ways to disconnect it, but it's difficult and messy.

Lakeowner

Sat Apr 12 2008, 09:49AM

Registered Member #1370 Joined: Mon Mar 03 2008, 09:01AM
Location: Finland
Posts: 56

I went to a junkyard two days ago, and I was allowed to search from junk heaps. Actually I looked for transformer cores, but there were also lots of NSTs with ratings of 520VA and less. I took one for test to home (for free), and it worked perfectly :). At the bottom:

I recommend to check out your local junk stations.

lpfthings

Sat Apr 12 2008, 11:35AM

Registered Member #1361 Joined: Thu Feb 28 2008, 10:57AM
Location: Cairns, Australia
Posts: 305

It's not common for HV hobbyists to actually buy NST's, they usually scavenge them, get failed ones and repair them, or call the neon sign shop (thats how i got mine, for free). What i did, is just looked up a neon sign shop in the phone book, went down on a saturday and asked if they had any OLD TRANSFORMER STYLES that i could use for HV experiments. The guy went right to the shelf of NST's, grabbed the BEST looking and highest voltage NST he could find, told me how to wire it up and sent me on my way. Nice guy. I am 14, and he didnt even hesitate giving one to me (i am careful, dont worry lol) You still have to be very careful with NST's, they arent as likely to kill you, but it is still possible under the right conditions, but what isnt

Dragon64

Sat Apr 12 2008, 12:10PM

Registered Member #1438 Joined: Sat Apr 12 2008, 12:57AM
Location: Canada
Posts: 218

I phoned into our local NST and asked them if they had any failed NST. They said that they had none currently and said that they might phone me if they find one.

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