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Registered Member #1408
Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679
Restaurant supply places get a LOT of commercial-level microwaves that they really just give away. HOWEVER if you can get matching units especially Toshiba's, they have a seriously tall, big-ass MOT. Not only does it PUMP (I think they are 3.2k) but they are very easy to work with because they are about 8" tall and have a great deal of room.
Registered Member #195
Joined: Fri Feb 17 2006, 08:27PM
Location: Berkeley, ca.
Posts: 1111
if you want power dont put the mots in series put them in paralell and in phase. Use about 4 for a 4ft coil. if you paralell them the current and power can be increased. you could do a series paralell where 2 are phased in paralell and the other two are are paralelled but out 180 out of phase with the first two for a 4200vac. if you can find the right capacitor ie maxwell cap or pusee cap there is no need for rectification and run it like ar regular spark gap tesla.
Registered Member #122
Joined: Fri Feb 10 2006, 12:55PM
Location: Milano Italy
Posts: 148
I only have 2 25ma 15kV NSTs, and i'm not sure i want to spend all the money to get some more
First of all YOU NEED TO BE SURE ABOUT YOUR POSSIBILITIES, YOUR BUDGET AND YOUR GOALS otherwise you will only spend huge money to trashing everything (exactly as your Xray machine!), coils are expensive and require many theorical and pratical skills
second, 6 foot of sparks seems way too long for a beginner (expecially if he have only 16 years old), something between 50 centimeters and 1 meter is much more easy to build (for a spark-gap coil of course) and is surely a great starting point for a beginner
third, DON'T USE MOTs! MOT's are difficoult to manage on a spark-gap coil because the output voltage is annoying low, the current is insanely high (hence the spark-gap can be difficoult to start and quench), they require an external ballast and there are EXTREMELY DANGEROUS, the only plausible exception for using a MOT for the first teslacoil is a VTTC NST's are really easy to manage instead because their output is OK and they didn't require anything to run (except some overvoltage protection) Of course, PT's or pole pigs are ridiculous for a beginners
fourth, a syncronous rotary spark-gap can give you excellent performances on well-designed coils but is almost impossible to build without a lathe, a milling machine and some mechanical skills because the maximum ammissible tollerances and imbalances are really low on a disk spinning at 3000 RPM (3600 RPM in US), if something goes wrong the disk will start to vibrate violently and could literaly explode. A simple Richard Quick style spark gap will be enough for a beginner.
i personally suggest a simple NST-powered coil, running in a quarter wave resonance with a Richard Quick gap on a larger than resonate static mode (LTR-static), the ideal sparklenght for a beginner is included between 50cm and 1 meter. i also suggest to design your coil as well as possible to get the maximum possible sparklength with a modest supply, my coil can reach 1,4 meters with only 700 watts! if you're not happy about this configuration i can suggest to build a VTTC instead (powered vith a single MOT + voltage doubler, with a single 833 or GU81 and autotransformer primary), the sparklenght will be less but at least you can play with sparks with neons, hot sticks and even bare hands!
Registered Member #2893
Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242
Okay, so i saw EVR's video , and i definitely want to build an audio modulated SSTC. I have an old keyboard that needs a home too (even though i can't play it for the life of me). However, i really know nothing about SSTC's. Is there anything you guys can tell me about them. I've shortened my spark length goal to about a meter, although bigger is still better.
Problem is, i still need to sell the rest of that x-ray stuff to have enough money to do this.
Registered Member #2893
Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242
Well, i just tried playing the piano again, and that is not going to happen at all. So i really don't care anymore about sound modulation. Anymore, even though it is really cool.
Registered Member #122
Joined: Fri Feb 10 2006, 12:55PM
Location: Milano Italy
Posts: 148
Grenadier, i think that you haven't entirely read my message:
and i definitely want to build an audio modulated SSTC......However, i really know nothing about SSTC's. Is there anything you guys can tell me about them.
First of all YOU NEED TO BE SURE ABOUT YOUR POSSIBILITIES, YOUR BUDGET AND YOUR GOALS otherwise you will only spend huge money to trashing everything (exactly as your Xray machine!), coils are expensive and require many theorical and pratical skills
A SSTC coil isn't exactly a starting point for a beginner and a modulated coil capable of 1 meter of sparks is a challenge even for a well skilled coiler who previously worked with SSTC can be your tenth coil if you previously worked with smaller solid state ones but surely it cannot be your first coil!
I've shortened my spark length goal to about a meter, although bigger is still better.
Please notice that my sparklength suggestion was clearly dedicated only to a spark-gap coil with the simplest topology!!!!!!!!!!!!!!!!
something between 50 centimeters and 1 meter is much more easy to build (for a spark-gap coil of course) and is surely a great starting point for a beginner
i personally suggest a simple NST-powered coil, running in a quarter wave resonance with a Richard Quick gap on a larger than resonate static mode (LTR-static), the ideal sparklenght for a beginner is included between 50cm and 1 meter. i also suggest to design your coil as well as possible to get the maximum possible sparklength with a modest supply, my coil can reach 1,4 meters with only 700 watts!
if you dislike this configuration you can build a simple VTTC instead (with about 30cm sparklength) and if you want the audiomodulation, you can make a smaller VTTC (about 10cm spark) or even a tiny SSTC (few centimeters sparks, altough i think that a SSTC isn't a big idea for a beginner)
Problem is, i still need to sell the rest of that x-ray stuff to have enough money to do this.
a medium sized SSTC will cost MUCH MORE than your xray machine, trust me, a SSTC isn't the right way for you!
Definitely, you need to forget the rest and you should think at something like this please note that these shots was taken 9 years ago, this was my first coil and i was the guy!
or maybe something like this other Again, this is one of my coil!
And finally......... this is my 100th post here!!!!
Registered Member #2893
Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242
Okay, so i'll go with a DC spark gap coil then. I didn't think a SSTC was that more expensive, expensiver? [i].
At any rate, i wont be starting this project for a little while anyway. I've always wanted a coil, but when i had a decision to make, i (stupidly) chose the x-ray.
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Pros and cons of tesla coil primary supplies.
