HOW TO BUILD A TESLA COIL
by Steve Gantt (713) 684-6269 (VOICE) (713 688-2058 (FAX)
I like alot of other folks seem to be driven to explore the uses of high voltage devices. I do not know why exactly. Hey, maybe I was abducted by aliens, and realize that by the understanding of how high voltage and frequency react on matter we might be able to beat the impending alien invasion… Or, then again I might just find this fascinating . At any rate, I thought that I might share my experience in building a tesla coil, and give you some pointers.
Question : Building your own tesla coil is about as difficult;
A. as baking your first cake B. rebuilding your first automobile engine C. A final exam on "Nuclear Fusion as it relates to Electro-
dynamic Variations in Adjacent Ferrous Materials as Opposed to Standard Electromagnetic Pulses"
( The answer is A )
You should be able to complete this project in your spare time in about a week. Five days you will be required to watch the DISCOVERY Channel or any other channel that will help you through the boredom of winding the tesla coil (often called the secondary).
First you will need about $ 70 to get all the materials (see the attached parts list). After you have purchased everything you need to build the coil, start on that first. The Tesla coil itself is constructed from a 3 foot piece of 4" PVC pipe (if you go the hardware store & want to impress them, tell them you need 3 feet of 4 inch Schedule 40).
Next you will need about 1 & 1/3 pounds of # 26 AWG magnet wire. By wire by the pound ? Yes ! that is how this wire is usually sold. Get two pounds it's not that expensive, and besides you might want to experiment with it later. Now CAN use #30 AWG or # 28 AWG or # 24 AWG but if you use other wire the coil won't work as well ( the coils is based on some complicated algebraic formulas, and is dependant on # of turns, length of wire, etc.).
Now drill a small hole each end of the PVC about 1/2 inch from the top and bottom. Shove one end of the wire thru one of the holes and leave about a foot of wire on the inside. Take some tape and put it over the wire so you don't pull it out like some dummy I know did (me). Now comes the winding…
Place the PVC on the floor in front of the TV, turn the channel to some movie, the Discovery Channel or something else, get you something to drink, and have a roll of tape a pencil and paper within reach. Now start turning the pcv allowing the wire to wind around it. Count ten full turns. Move all the wire down so that it looks real pretty and that no wire has jumped on top of another. Kinda pull it tight, place some tape over it, and mark down ten on your piece of paper. You are now 1/160 th's the way there. You will need a total of 1600 turn on this PVC. Make sure that no wire is on top of another, be sure to pull it tight ( but DON'T BREAK THE WIRE !). If you DO break the wire or you run out in the middle of the 1600 turns then…
Use some sandpaper to get the enamel off the end of the wire and solder the two loose ends together. Make it a real pretty solder job, no sharp edges, no blobs of solder, etc. then coat the solder joint with your favorite high voltage dope, or non-metallic fingernail polish, whichever you have handiest. Keep winding, keep counting. Keep putting that tape on so it doesn't unravel on you. When you finish counting to 1600 then …
Cut the wire so that you have about 24 inches of wire left, place it through the other hole in the pvc. DON'T take the tape off yet. Secure the wire on the inside with another piece of tape. Now take your almost finished tesla coil outside and start spaying it with "Non-conductive Fast-Drying Clear-plastic acrylic paint" ( Go down to the hardware store & get a couple of cans of clear acrylic spay paint). and put about three coats of paint on the coil. Now take the tape off, check for loose wire and wire that has gotten on top of other wire (Take time to do this right. It's not difficult, just time consuming). Now spay about another 6 coats on. If you have finished with the six coats, just use up the rest of the paint with extra coats. Be sure to let this stuff dry well between coats.
Okay now we can start on the Driver…
If you can solder & read schematics then go to it & skip ahead to the OPERATION Section…
If you have never soldered before, or have never built any circuits before, then I suggest you practice first.
Take the perfboard and place the LM567 in the top third of the board about four rows from the top. The LM567 will have either a notch in the top or a dot over pin 1. Now bend over pin # 8 ( it is not used and will help hold it in place for you. Next take your .1 MFD caps and put then in place one hole over next to pins 1,2 & 4. Solder one leg to those pins. Now hook up everything else as shown in the schematic.
To make T1 you will need to take the AMIDON ferrite core. Remove the bobbin and wrap 15 turns of the # 26 AWG , spaced evenly, leaving about a foot of wire at both ends. Then wrap it with tape. Now mark the ends of the wire so that you know what they are. Now take the other piece of the ferrite coil and wrap about 120-150 turns on it leaving about a foot of wire on each end ( yes, use the same #26 AWG wire). Cover that with tape. Now put the bobbin back in. Now wrap the entire thing with a few layers of tape, making sure you know which wires cane off of the bobbin (primary 15 turns) and the other (secondary 120-150 turns).
After you have completed everything, co back and check all of your connections. Check them again. Then get a friend to check them.
If you don't have a 18-24 vdc power source you will have to build one. Use the package called 24VPOWER. This file is with this package.
Set up the TESLA coil so that it stands vertically on a table. Remove everything from around it, especially diskettes, VCR tapes, credit cards, etc. hook the bottom wire from the coil to the tesla coil driver. The upper wire should remain inside the PVC, taped to the side. Put the switch on TUNE (if you don't do this you will blow the LM567) and apply power ( turn it on ). Adjust the trimpot so that both LED's are about the same brightness. Now you can switch off the tune switch.
You should be operating now. Hold a florescent tube up to the top portion of the coil and it will glow. You will see some little sparks if you touch the coil on the top portion. You now have an operating Tesla coil.
What to do if you run into trouble.
1. Check all your connections 2. Have a friend check all the connections. 3. Call you mother and have her check all the connections. 4. Use a multimeter & check the voltage between ground & pin
# 4 of the LM567. It should read about 8 VDC. If not and step 5 checks okay then replace the 7808
5. Check the voltage between ground and the input of the
7808. It should be between 18-24 VDC. if there is no voltage then you have a bad power source.
6. Check voltage ( frequency if you have it) on pin #5 of
LM567. If there is any voltage or frequency, then the IRF511 is bad, replace it.
7. Other things to check after the above.
a. Make sure the primary and secondary of T1 are not reversed. b. If the LED's glow, then everything is operating ok up to that point. Use a multimeter & check OHMS between the upper and lower wires of the tesla coil. It should read about 0 ohms.
c. Pray d. Spit on it e. Use abusive language f. call me