If my understanding is correct, one needs to have a firm grasp of alternating current, inductors, capacitors, and the concept of resonant circuits and be able to use software (Tesla coil simulator) to simplify the actual calculations.
Assuming I were to begin by with a spark gap coil design (as it’s the simplest in theory), what is the best type of transformer to charge the primary tank capacitor?
Is a solid-state type easier for the first timer to tackle?
The best place to start is at the auto wreckers. I remember building these many years ago, So you need an old 12V ignition coil to start with that you can either take appart and modify or build a multivibrator circuit to pulse it with. In the old days we just used a steel strip mounted next to the core of the HV coil (That is sttripped appart). That strip is configured with a set of points (Normally closed) so that when 12V is applied to the coil, it magnetizes and pulls the points open, breaking the circuit, and the whole process repeats giving you the simple vibratod circuit. Dong it electronically will require a good power transistor that can handle at least 10-15 amps, but it would be quiet. Drive it with a 555 timer circuit to get the frequency you want.
After you've got that working and get the HV out, that goes to the (Im not sure of the exact details) large #14 -#12 Gauge solid wire coil that drives the Tesla coil. I can best describe it by telling you to wind the tesla coil (HV out) over a long cardboard tube about 2-3"diameter, depending on the length you use. About 3 ft is a good size. Use #26 or finer magnetic wire and wind it carefully from one end to the other. I'm not sure of the connections but the top wire of the tube gets connected to your foil or whatever you use for the ball on top. Dont forget to scrape the coating off to expose the magnetic wire for soldering.
Ok, I believe the bottom of the coil is connected to the bottom of the driver coil or a ground. The driver coil is about an inch larger than the HV coil and is about 4-5 turns. All windings are not scramble wound but neatly beside the previous windings. The Large driver coil is then spread out so there is a 1/4" to 1/2"spacing between windings. This coil gets mounted to hold it in position around the bottom of the HV coil and up from ground.
The HV coil now goes one wire to ground, the other to your homemade spark gap which should be adjustable from about 1/8"to 1" and then to the top wire of the driver coil. So now to get this going, you set yor spark gap say at 1/2" and apply 12V to your ignition coil. If it works, great, if not, turn it off and narrow the gap until you get a spark across the spark gap.
That's about all that I can remember except that it takes a long time to wind the coils, but the results are worth it.
Anyone els amy have some more details that I have left out, or maybe there's a schematic on the web to follow.
A simple Tesla Turbine is rare earth magnets and CD disks spun inside or outside coiled copper. Use algebra to identify your sine gives structure to the copper coils.
Using an old permanent magnet motor: remove brushes, attaching small RE magnets to the end of the fins on both sides (if possible) is easiest to turn a motor into a generator.
A Tesla Turbine is not a Tesla Coil. A Tesla Turbine is a a form of pump for air or liquids that uses spinning flat plates and the boundary layer effect to fling the fluid being pumped.
What you describe sounds like an "influence machine" close to the one produced by Holtz. The better-known version of this is the Wimshurst influence machine. One of these can be seen operating in the 1931 Frankenstein movie. (The same machine - heck, all the old-timey mad-scientist stuff from that movie - was also used in "Young Frankenstein.")
While the use of a cardboard tube to wind the secondary coil is the old and established method, it has some inherent problems. Cardboard tubes, unless heavily varnished, which only works well on the outside, tend to be sensitive to humidity. This means you have to worry about providing a very dry storage area. Cardboard tube wound coils that pick up too much of a moisture content are subject to shorting, flash-over and variations in voltage output. Plus they produce ozone, which is an unpleasant nose and throat irritant. Cardboard tubes are also not well suited for large and heavy coils, because their soft composition makes them very difficult to secure rigidly to your base board. The answer is both inexpensive and easy to obtain. The plumbing department of Your local Lowes or Home Depot has a variety of rigid PVC drain pipe and water supply pipe that comes in a range of diameters from half an inch up to six or eight inches in the case of drain pipe. Color choices are limited to white and grey, and as a plus, you can easily bond the ends to like material or simply buy the matching pipe end plug to securely attach it to your base board.
Ozone is produced by the discharge, which ionizes the air around the output terminal. Cardboard has nothing to do with ozone production.
The other tesla coil in my 8th grade science class had a 5-foot-tall, 6" diameter secondary (output) coil wound on a fairly hefty cardboard tube, which worked just fine. The tube was painted inside by fogging spray varnish into it, with a desk fan sitting beside (not in line with) the other end, blowing away from the paint nozzle. The draft from the fan sucked air through the tube, (unevenly) coating the inside with varnish. After the coil was wound, my friend slathered the whole thing with varnish to keep the windings in place. Reasonably waterproof, and he wasn't planning to leave it out in the rain.
A wood plug was then glued to the tube by inserting it into the bottom end; the plug was bolted to brackets and thence to the plywood base. Easy to disassemble for transport and reassemble for demo.
My 1967 tesla coil used lucite tubes: the primary was 4" OD, the secondary was 2 OD. Lexan or plexiglass are related, glue-able products and should work just as well. Varnish (NOT polyurethane!) over the coils to keep them in place.
I built a Tesla coil in, uhhhh... 8th grade, around 1967-68. So, yeah, it possible!
Mine was a crazy thing built around a high-power Hytron RF oscillator tube - no spark-gap or huge glass capacitor, like one a classmate built. There was a neon sign transformer in it, feeding the secondary. The tertiary (final) coil I spent most of a day winding by hand with 40 or 42-gauge wire. All the internal wiring was spark-plug wire.
I couldn't measure the frequency, but the Popular Science article I built it from said it produced about 60 kV at about 500 kHz. The neat thing was the discharge frequency was high enough to be conducted over the skin, so one metal screw, and voila! the flourescent lamp I was holding was bright around my hand and faded to dark at the ends.
I just looked at Eastern Voltage Research - good tip from Pd5! Their stuff is wild! (I trust you're not thinking about building a megavolt monster!)
There are entire clubs of people that do nothing with their lives other than building Tesla Coils of all sizes, solid state or convention types driven by neon sign transformers. All you need do is Google "Tesla Coil". The list will be endless. One can even buy relatively small secondary coils pre-wound.
Please read the following very carefully. I realize there are many political beliefs that are aligned with this technology, more so perhaps than most other technologies and so there are people who are ardent Tesla defenders. I am not attacking Tesla.. but the guy was archaic and since his pivotal work, WE and our collective understanding of electronics... have moved on.
There is an oddity about this list... I think one has to speak about the application, or rather the purpose one has, not just the device, in order to actually understand, what to do, before one builds anything.
For instance, when people mention Tesla Coil, they are speaking about a bizarre form of low frequency RF device. It is a kind of resonant air wound auto-transformer who's whole purpose seems to be, to emit large sparks and pyrotechnics into the air around it, in order to thrill and charm onlookers. This 'thing' has manifested itself into perpetuity, because Tesla (the original inventor) had such a poor understanding of how to approach his dream of 'free power', that he actually thought this thing would transmit usable amounts of 'free energy' to people miles away, with any kind of cost effective efficiency. Because of early success in the design of our general AC Power Grid, he... was over confident. When he died, he left patent filings detailing his ultra inefficient and poorly thought out structure, and people have been building them, in a kind of mystical zeal, just like he did, since. Those are quite simple to build, and even little kids have done so, to the amazement of their parents and friends. But as a 'free energy' transmitter, it is totally inadequate! So... the purpose and application of YOUR DESIRE to build a TESLA COIL, must be defined, before merely doing what everyone else has done before you... or you will end up with something that shoots sparks and pyrotechnics, and simply amaze your friends and family... but not do much else.
Sounds like a bit o' Marxist-Leninist dialectic misapplied.
There essentially is no technical application for a Tesla coil other than emitting sparks and making fluorescent bulbs glow without attaching wires.
There IS the application of entertaining people. There IS the fun of building something just for the fun of it, and the getting of satisfaction when that something works as intended. There doesn't have to be any further justification. There doesn't have to be any justification for building any non-weapon device save amusement.
There is also the potential for intriguing a youngster to science and engineering. Maybe the next Tesla.
Dude, the guy didn't ask for a philosophical discourse, and why he wants to build one is pretty much none of your business. He just asked if it's possible to build one.
The answer to which would have made itself readily apparent by simplyGoogling "home made tesla coil"...
Contrary to what some of the posts say Tesla coils are just plain fun! Reading the discussions on building a coil I saw no mention of a tuning capacitor. The coil is a resonant circuit. The HV coil has a natural rsonant frequency and for best performance the low voltage driver is set up as a tank circuit and should be tuned to the frewuency of the high voltage coil. This capacitor can be made from glass plates and aluminum roofing stuff. These items can be found a a Home Depot or Lowes. Tuning will be tricky depending on your skill set. You ned to calculate the value of the capacitor and the primary coil. There are tools to do this that can be found on the net. Finding the resonant frequency of the high voltage coil is a little more tricky. One method, is if you can find one, is to use a grid dip oscillator. (I guess I showed my age using the term grid!) Another approach, which I haven't tried is to drive the primary coil with a power amplifier driven by a function generator. Connect the amp output to the primary coil through a 8-10 ohm resistor. Hang an AC voltmeter or an oscilloscope probe over the HV coil and ground the meter to the other end. Scan the range from 20 kHz to 500 kHz and look for the meter to peak. The peak should be at the coil self resonant freqency.
You still can be able to get the coil optimized without all this, but it will take a lot of tweeking to get there. Good luck and have fun. I have two coils in my garage and one of these days I will fire them up again. One of the coils goes back to high school days when a buddy of mine and I started to build one from a Popular Science magazine artical.
Zigg: If you can check out RM CYBERNETICS (rmcybernetics.com) in the UK. They have ignition coil driver circuits.
Power Pulse Modulator PWM-OCXI v2. 12-30v in, 0-340v out. Max out current 9A. Peak 120A. Has an i/o for a microcontroller interfacing. .01Hz-1.5MHz frequency range with adjustable duty cycle. Priced at $99.10 (ouch).
Has anybody ever run 340V into a 12V auto ignition coil and lived to tell about it? Remote control brush fire circuit. A one shot wire guided weed burner. Maybe we can box em up and sell em to the DOD.
What we want is a cheap down and dirty easy to build adjustable duty cycle - adjustable frequency coil driver kit without the high cost so we can charge large capacitors through an ignition coil.
This energy when released through a diode protected circiut should make some really big sparks.
I dont know if it still exists, but there once was a Tesla Coil Builders Association. I was involved in building a 5 foot one. A real mean machine it was. I designed its resonating capacitor, which withstood over 10kV and would completely discharge when shorted with no residual charge. I was not present when it was done but bad idea as the sound was louder than a heavy guage rifle shot! It is potentially very dangerous to build a Tesla Coil as the primary resonatinc capacitor will kill instantly (more than one person) if touched when charged even if not connected to anything. BE CAREFUL and have fun!
I still have the July 1964 Popular Electronics I built the Big TC from. It also has the Li'l TC that uses two vacuum tubes. Does anyone want me to scan and send it to you? By the way, we had an attachment that, I don't remember what it was called maybe a Jacobs Ladder? It had two wires that formed a spark gap. It formed a "V" shape. The spark would start at the bottom and climb to the top and disappear. Then start over. Way cool.
John, that would certainly be cool to see. Perhaps you'd consider uploading the pictures to an online album and sharing it? or perhaps just upload a couple of the more interesting pages here?
Nikola Tesla was trying to power everything wirelessly. You were going to be able to just pull the energy out of thin air. He was ahead of his time. What we do know today is that the intense electrical field the Tesla coil develops is not good for long term exposure. However, what is really awesome is to see is the look on a kid's face when you turn it on and get that huge electrical spark. Then everyone is dumbfounded when neon or fluorescent lamps are brought near (not in contact with) the Tesla coil. With no wires they light up on their own.
We built one in High School in 1969. I still have the original Popular Electronics we built it from. Read and heed all of the safety suggestions. Below is a link to the Popular Electronics article already on the internet.