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Registered Member #1034
Joined: Sat Sept 29 2007, 12:50PM
Location: Chillicothe, Ohio
Posts: 154
In a lot of ways the mini Tesla coils are more fun than the big ones. More corona, more ozone , less noise , finer sparks and you can get much closer to it. Whenever you show someone a big Tesla coil it is always good to show them a mini Tesla coil first. It gives a good illustration of what happens when every thing is scaled up in size and power.
The picture here shows a good example of a person letting current from a semi-large disruptive discharge Tesla coil flow though his body. There is a 40 watt light bulb being lit to full intensity which means the average current flow must be about 340 ma. Don't try this at home !
Registered Member #1408
Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679
Generally speaking, it seems that NST and Ignition Transformers are the best best of building a TC but the sources I am finding are quite few. I am asking a rhetorical question here (as I'm aware of the rules of the forum) & am not selling, etc, but would there be an interest or a likelihood of selling off a quantity of low current transformers on Ebay or even here, if I could get a quantity of them? Is the level of interest in HV experimentation high enough so there is a real market for these transformers? I just may be able to gather a good deal but only if I were to buy several.
There are companies that have Ignition transformers for oil furnaces but they say that the transformers are quite dirty and that they would need a great deal of clean up for use in hobbyist HV applications. I live in Arizona and have no experience with Ignition Transformers. What do those companies mean by the expression "awful dirty: would take a great deal of clean up"??? How dirty could they be???
Registered Member #1157
Joined: Thu Dec 06 2007, 12:11PM
Location: Houston, TX
Posts: 307
quicksilver wrote ...
There are companies that have Ignition transformers for oil furnaces but they say that the transformers are quite dirty and that they would need a great deal of clean up for use in hobbyist HV applications. I live in Arizona and have no experience with Ignition Transformers. What do those companies mean by the expression "awful dirty: would take a great deal of clean up"??? How dirty could they be???
Lets assume the average heating oil used in homes is probably something like Kerosene. When that stuff burns, it is sooty, greasy, filthy. Probably gummed up with gook and rust, and you'd never get the smell out of your hands. . .
But, me being a dumpster diver, there is nothing too filthy for me. Gimme a can of Gum-out, a pile of old t-shirts to use as rags, a six-pack of beer and I'd call that a good Saturday in the garage.
Registered Member #1157
Joined: Thu Dec 06 2007, 12:11PM
Location: Houston, TX
Posts: 307
adamjon858 wrote ...
Alright, so I'm going to need primary and secondary coils, a transformer, and a mmc?
Would this work for an mmc?
Would this work for power?
Also, what's the safest way to hook one of these "plugless" power supplies into an outlet?
Also, Steve mentions tuning the LC circuit between the tank and the primary coil, is this very hard to do? I don't have an oscilloscope...
Tesla stuff will have everything you need. He is expensive, but he'll have what you need. Browse his store and get an idea of what you'll need to look for.
That Cap you have tagged would probably not work very well, the capacitance is kinda low.
The power supply you have tagged, what is that? a rack mount DC supply? If you need a low volt DC power supply, Uzzors has a nice ATX hack on his site that you probably already have all the stuff for in your garage already.
I'd say read a bit more about Tesla coiling before you actually buy any stuff. When I first realized I wanted to build a Tesla coil, I bought a whole box of capacitors on ebay because they said "Tesla Coil" on the auction, and only after I read a bit more did I realize that the ones I bought were useless. People put "Tesla coil" on a lot of stuff on ebay that has absolutely zero to do with tesla coiling because they either don't know any better, or because they know that someone out there will bite on the baited hook.
Read all the good sites, see what folks out there are using, and try to follow what worked for them on your first coil. Then once you've got one up and working, and understand how it works, then you can experiment with new stuff.
Try deepfried neon. Or Terry Fritz. Or Even Ritchie's site.
Registered Member #952
Joined: Mon Aug 13 2007, 11:07AM
Location: Finland
Posts: 388
adamjon858 wrote ...
Alright, so I'm going to need primary and secondary coils, a transformer, and a mmc?
All of the other parts seem to be just small electronic components that are readily available online.
Could anyone point me to ebay auctions for these things? I want to make sure I don't buy the wrong thing.
Would this work for an mmc?
Would this work for power?
Also, what's the safest way to hook one of these "plugless" power supplies into an outlet?
Also, Steve mentions tuning the LC circuit between the tank and the primary coil, is this very hard to do? I don't have an oscilloscope...
Which are you actually gonna build? SGTC or SSTC?
You won't need a mmc in a solid state tesla coil. 24 volts isn't enough for a spark gap tesla coil.
That power supply is useful for SSTC. Its output current is a bit low, though.
LC tuning circuit is needed in a SGTC, not SSTC. Solid state coil are tuned by 'solid state tuning circuit', for example Steve's Class E coil takes feedback from the coil with an antenna, it's fed through an amplifier (gate driver) to mosfet gate and voilá, it's automatically in resonance.
Either way, you won't need a scope to tune the LC circuit in SGTC (your scope would die if you hook it to the sgtc primary circuit). You just need to get a cap that is approximately resonant and then try with different number of primary turns to get exact resonance.
Registered Member #952
Joined: Mon Aug 13 2007, 11:07AM
Location: Finland
Posts: 388
Read this:
Steve's page wrote ...
L1 and C6 make up a tuned circuit of sorts. Basically what happens is when the MOSFET turns on, current builds up in the primary coil and any other leakage inductance in the circuit. When the MOSFET opens up, the stored energy is released as the magnetic field collapses. This generates an EMF which charges the capacitor across the MOSFET. Once the capacitor has reached its maximum voltage, it begins driving voltage back through the primary inductance (voltage falls). Our hope is that after the voltage peaks, it returns back to zero smoothly (meaning the circuit is critically damped). This means that there is no turn on switching loss since the voltage across the MOSFET is zero when it turns on, and if the voltage doesn't dive lower than zero, there is no current flow in the reverse diode.
Class E doesn't need a big, high energy tank cap as SGTC does. The cap is there, as Steve's page said, for damping the circuit so that the voltage over the MOSFET is zero when it switches on. That reduces greatly the switching losses. Usually the tank cap is just a single or a few small capacitors. You will need a scope for Class-E tuning, that's pretty different business than SGTC tuning.
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Thinking of building Tesla Coil
