First things first:

DISCLAIMER: I am not responsible for any injuries or property damage that may befall you from following this instructable. High voltage electricity can be DANGEROUS and should only be worked with at your own risk. Proper safety precautions should always be followed. 

That out of the way, welcome to my first instructable. Seeing as this is my first, any suggestions for improvements are greatly appreciated. Just go easy on me.
This is intended to be a how-to guide for a newbie to high voltage (like myself) looking for a quick, cheap, and relatively safe project. Although this is not a true tesla coil, as it does not utilize a resonant air-core transformer or operate at high frequencies, in effect it is similar. It still throws out plasma discharges from the top load and about 3.5 centimeter arcs to ground. Estimated output is about 100kv.

Step 1: Parts and Pieces

There aren't many parts to this build, and most can easily by scrounged from old TVs and other electronics or be bought for cheap. The following is needed:

Bug zapper racquet: This can be purchased from Ocean State Job Lot for about 5 bucks, and is nifty for fending of mosquitos or high voltage experiments. There are probably other types of devices very similar, but I would recommend finding the racquet pictured to insure the internal circuitry is the same.
Flyback transformer: Any flyback transformer will do, though the bigger the better. Don't kill yourself looking for an old non-rectified design, since there are no benefits of it for this circuit.
Random assorted hardware: This circuit requires a spark gap to be constructed. The design of the spark gap can vary, as long as the two ends where the arc jumps is rounded, and the gap adjustable. For mine, two Erector set brackets were used. One had a ball bearing soldered to it, the other a nut over top the hole, so a bolt with an acorn nut on the end can be threaded through. See the attached picture for the details. 
2xAA battery holder: Can be purchased from Radioshack or the bug zapper handle can be used to hold the batteries.

Additional Capacitors: Should be rated for at least 1.6 KV. The Bug zapper already contains one, but for bigger sparks more can be used.
Toggle Switch: The switch on the board of the bug zapper can be difficult to use, and because of the design of the bug zapper circuit, floats at high voltage, leading to a shock hazard when it is exposed. Because of this, a new switch is recommended.
Pen body or other plastic tube: To elevate the top load
Top load: I used a ball bearing, but anything smooth and without sharp edges or points can be substituted. 

Of course, solder and a soldering iron as well as other general tools are needed, and wire for connecting everything together
<p>I finished the coil using the following : BD135 transistor, one Resistor - 47k 1/2w, 9V battery, 6 turns primary coil, 2400 turns secondary.</p><p>There<br> is no spark, but it successfully lights lamps. There is though a small <br>problem. When I approach a lamp to the coil, the lamp lights but if I <br>leave it there <br>the lighting lasts only for 80-90 seconds and then fades away.</p><p>I have to close the circuit for some time and open it again to make it light again.</p><p>Have you faced this problem? Can you help me with this?</p><p>Thanks for your help</p>
<p>you should use a ceramic cap i dont know how meny farads but you do simple calculations...</p>
<p>could i use a 7kv generator to power the flyback instead of the bug zapper?</p>
<p>Thanks, I successfully made a Tesla Coil! BUT. The arcs from my electrode are roughly 1 inch, which is fine, but my flyback transformer is exerting arcs of electricity out the back (Near the high voltage output wire), and this isnt from an open pipe for wires, I mean literally straight out the back of it. The largest was 3 inches, why is my flyback doing this and why are they larger than the arcs from the electrode?? Thanks in advance!</p>
Insulate them the high terminal arc would work better
Is the flyback transformer required can do it by just winding the primary and secondary coil
<p>what did you use for the ground connection.</p>
<p>Could I use a microwave capacitor in the capacitor bank? What about an electrolytic one?</p>
You certainly wouldn't want to use electrolytic capacitors because they would explode/experience other malfunctions due to the issue of polarity and the voltages involved. I'm not sure about the microwave oven capacitor. All I know is that I have seen people use them in other high voltage projects.
<p>Awesome! I made this late lat night and it works great! The arcs are infrequent but when the spark gap fires the arcs are huge! I have been thinking about increasing the output with an array of saltwater capacitors.</p>
<p>Great job also salt water capacitor is a great idea i added it to my flyback and got thick blue arcs and do you connect the zapper to the primary of the flyback?</p>
Yes, you connect the outputs of the zapper circuit to the primary coil. You actually have two options: find the actual pins for the primary or wrap some wire around the core. I would recommend the first option, but both will work.
<p>Hey i also have a toshiba flyback with the datasheet (bsc25-t1010a) and im not sure which is the primary in the schematic it says h h1 h2 h3 h4 etc. no primary</p>
<p>I need a voltage pulse of 3.5 kv. Can i get it with this circuit or does it produce only very high voltages. </p>
<p>The bug zapper circuit alone produces about 1.75 kv. By using a 1:2 step up transformer you could reach about 3.5kv.</p>
<p>and by 1:2 stepup transformer I mean in place of the flyback transformer. </p>
<p>The zapper should be connected to the primary of the flyback right?</p>
Does it work???
<p>Would it be possible to connect some sort of &quot;microcontroller&quot; to be able to play musical tunes? </p><p>(like in this project https://www.instructables.com/id/Build-a-Musical-Te...</p>
<p>I don't have a flyback transformer on me. Could I just use another transformer from a different bug zapper? Isn't that big black component with the yellow strip on the zapper circuit already a flyback transformer? </p>
Hi i have made the almost setup and i am facing the problem in grouding the terminal of secondary coil can you please help me or suggest me what to do for grouding the terminal
<p>sorry im not sure why it got posted more than once.</p>
<p>I'm extremely new to all of this, and im building a tesla coil (or something similar) for a science project. I was wondering if there was a certain type of wire i needed to use, or if it didn't matter. And if there is anything i need to know or any videos or something that would be good for this can someone please let me know? thanks</p>
<p>I'm extremely new to all of this, and im building a tesla coil (or something similar) for a science project. I was wondering if there was a certain type of wire i needed to use, or if it didn't matter. And if there is anything i need to know or any videos or something that would be good for this can someone please let me know? thanks</p>
<p>I'm extremely new to all of this, and im building a tesla coil (or something similar) for a science project. I was wondering if there was a certain type of wire i needed to use, or if it didn't matter. And if there is anything i need to know or any videos or something that would be good for this can someone please let me know? thanks</p>
<p>I made it... but plasma discharges are not much longer. what should i Do ? Shall i add a step up transformer to the circuit ? i mean Can i connect the transformer to one of the wire outgoing from the zapper circuit to the primary coil ? or else suggest me a method plz.</p>
<p>not a tesla coil</p>
That can be considered as tesla coil as soon as can light up a lamp or can create a wireless energy
<p>It already is lighting up just in a spectrum can not fully see, it is also emitting &quot;wireless&quot; energy in the for a EMF. <br>If you are too stupid to think of a way to collect that energy then that is your own failure of an education not someone elses....</p>
<p>why do you think it is not a tesla coil?</p>
So are you using the flyback as your primary and secondary coils instead of just upping the voltage? Cause I don't see a coil on your torrid
<p>plzzzz help me i cannot make capacitor bank so tell me capacitor rating used in the project</p>
<p>unfortunately, I do not know the capacitor bank values, and I cannot really check since I am at college. But since this capacitor bank is not part of a resonant circuit like on a real Tesla Coil, the value does not have to be exact. Aim for somewhere in the .05 to .1 uF range for the whole bank </p>
<p>what is capacitor rating used for capacitor bank?????????????</p>
<p>I could only find rechargeable zappers. There are lithium batteries and the plug is connected to the circuit board. Do you know how I could rearrange this? I'm a complete beginner in these things.</p>
<p>This should work, though I don't understand why there appears to be five wires coming off the board- the two white at the bottom and white, yellow, and brown coming out of the top. It would really be a matter of identifying which wires go where. Whichever go to the mesh are the ones we want. </p>
<p>The bug zapper raquets are often on sale at Harbor Freight for about $3 US.</p><p>I buy them 6 or 8 at a time and give them as gifts...</p>
Nice simple design! I love it ! Going to try this! <br>
I have a 200v capacitor laying around, would that be uh... safe LOL of course the whole thing is dangerous, but I'm meaning more will the whole set up be able to withstand that kinda juice discharge? I know its only a tiny battery but still..
oh dear I just noticed my capacitor is rattling. Is this normal? Kinda a newbie to this and dont have any voltage meters to test it.
They should not rattle. And the capacitor should be rated for atleast 2000 volts. Thats the output from the fly swatter
I made a same 'Tesla coil' as you made but the problem i'm having is with the capacitors,using the one in the zapper itself are too weak,i made 6 bottle capacitors by myself but i was getting small arcs,and the capacitors made arcing sounds. I was thinking if i could use a large cap,about 1 micro farad?? <br>I cant get small ones and the one i make are too weak...
bottle caps can have issues. Make sure any fluid in the cap (if its a classic salt water cap) is below the top of the tinfoil that wraps the bottle. This prevents coronal loss. <br>also, the caps can be too small or two large. All i can say for sure is to try it. By tuning the combination of the capacitor and spark gap you can tune the coil
hmm. this cant be a tesla coil, the output is automatically rectified from the flyback,. nice one though
i know its not a tesla coil.... Its more of a descriptive use of the term. the differences between a true Tesla Coil and this project is highlighted in the intro
could you upload a schematic of your racket's board? i have all those parts already if i could see how they went together.

About This Instructable




Bio: Why fix it if it ain't broken? Because it's fun.
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