How to Build a Tesla Coil

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Introduction: How to Build a Tesla Coil

About: Devin is a cool guy, eh doesnt kill himself while doing stupid things, and doesnt afraid of anything.

This Instructable will walk you through building a medium sized Tesla coil.

Step 1: DANGER

Unlike some other high voltage experiments, a Tesla coil's streamers can be very harmful. If you are shocked by the streamers, you will not feel pain, but your circulatory and nervous system can sustain severe damage. DO NOT TOUCH IT WHILE ON UNDER ANY CIRCUMSTANCES.

Also, I don't take any responsibility for you hurting yourself.

This isn't to say that you shouldn't get into high voltage though, its just that if you are planning for this to be your first HV project, its a little to involved. Instead, try out a nice microwave oven transformer, and be safe!

Step 2: Gather the Materials

The total cost came to around $25, being that I already had the wood, Snapple bottles, PVC, and glue.

Secondary Coil:
  • A length of 1.5" PVC (the longer the better)
  • About 300 feet of 24 AWG copper enameled wire
  • 1.5" PVC screw-thing (see picture)
  • 1.5" metal floor flange with threads
  • Spray on enamel
  • Circular, smooth metallic object for the discharge terminal
Base and Supra-base
  • Various pieces of wood
  • Long bolts, nuts, and washers
Primary Coil:
  • About 10 feet of thin copper tubing
Capacitors:
  • 6 Glass bottles (Snapple bottles work really well)
  • Table Salt
  • Oil (I used canola. Mineral oil (horse laxative) it preferable as it doesn't mold, but I didn't have any.)
  • Lots of aluminum foil
And a HV power source such as a NST, OBIT, or other transformer that gives off at least 9 kV at around 30 mA.

Step 3: Wind the Secondary

Put a small slot into the top of the pipe to wrap one end of the wire around. Slowly and carefully begin to wrap the coil, making sure that you don't overlap wires or have spaces. This step is the hardest and most tedious part, but taking a lot of time will yield a very nice coil. Every 20 or so turns, put a ring of masking tape around the coil to act as a barrier if the coil starts to unravel. Once finished, wrap a tight piece of tape around the top and bottom of the coil and spray it with 2 or 3 coats of enamel.

Tips:
  • I built a rig for winding my coil that consisted of a microwave turntable motor (3 RPM) and a ball bearing.
  • Use a small block of wood with a notch in it to straighten the wire and tighten the coil.

Step 4: Prepare the Bases and Wind the Primary

Align the metal stand in the center of the bottom board and drill holes for bolts to go through. attach the bolts tightly upside down. This will allow you to put a base for the primary on top of it. Then bolt the primary's base in. Take your pipe and wind it into a pretty upside down cone (not the flat spiral in the pictures). Then mount it on the supra-base.

Optional was the addition of 2 supports that I zip-tied the primary to.

Forgot to add how to make the spark gap! It is just two bolts in a open-air wooden box, and they are adjustable for tuning, etc. See the last image...

Step 5: Build the Capacitors

I decided to go the cheaper route and build a capacitor. The simplest way is to make a salt water capacitor, using salt water, oil and aluminum foil. Wrap the bottle in foil, and fill it with water. Try to get equal amounts of water in each bottle, as it helps to keep the power output stable. The maximum amount of salt you can put in the water is .359 g/mL, but this ends up being a lot of salt, so you can tone down the amount a lot (I used 5 grams). Just make sure that you use he same amounts on salt and water. Now put a few mL of oil slowly into the bottle. Punch a hole in the top of the cap and put a length of wire in it. You now have one fully functioning capacitor, go make 5 more.

Optional: to keep the bottles in order, make or find a metal crate for them

As Glenn781 pointed out below, 6 Snapple bottles with a 15kV 30mA NST can be deadly! If you are using a NST like his, use 8-12 bottles, not 6!

Step 6: Connect Everything

Wire up everything according to the schematic below. The secondary's ground CANNOT be put to mains ground, it will fry everything in your house.

My Coil's Specs
  • 599 Wraps on secondary
  • 6.5 Wraps on primary

Step 7: Start It Up!

Bring it outside for it's first run, as it really isn't safe to run anything this potentially powerful indoors, there is a high risk of fire. Flip the switch and enjoy the light show. My NST, at 9Kv at 30mA, makes the coil give off 6 inch sparks. See it below:



Step 8: For the Future...

There are a few things that I realize I should change in my next Tesla Coil, one of the main ones being the design of the primary coil. It needs to be both more tightly coiled and it needs more windings. Also, i want to make a better discharge terminal. But, I have a new Tesla Coil planned for when i find the time and money, and it will probably be 6-7ft tall!

But for now, I'd like to admire other coilers hard work!
(embedding seems broken, but links work)
http://www.youtube.com/watch?v=iVmX2Ik4ylg

2 People Made This Project!

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1,022 Comments

0
nongbhud
nongbhud

2 days ago

Must primary be only copper tube? Can it be copper wire?
And must secondary coil be sprayed by enamel?

2
aishah.au
aishah.au

Question 1 year ago on Introduction

Would this be good for 9th graders school project

0
mitch.evans216
mitch.evans216

Question 6 months ago

Can you use this to power your home? Or at least some parts

0
davidr913
davidr913

Question 3 years ago on Step 2

is it possible to connect a 400kv highvoltage generator to the coil?

0
NoelA11
NoelA11

Answer 2 years ago

the taser type high voltage sources are DC and not suitable. they use a voltage multiplier to get the high voltage and this make the output DC and this will not work. A tesla coil runs on AC and needs to be HV

0
RayRay1132Gaming
RayRay1132Gaming

Reply 6 months ago

does that mean they can produce x-rays, if so how dangerous would you says they are. also can i use a taser source for a diy crt?

0
victorkerryotieno
victorkerryotieno

Question 7 months ago on Introduction

I don't understand the circuit may you please explain it in more detail

0
RayRay1132Gaming
RayRay1132Gaming

Answer 6 months ago

Its an air core transformer, when the spark gap fires it dumps the energy from the caps into the primary coil inducing a huge voltage in the secondary

0
m73humphrey
m73humphrey

Question 7 months ago

What sizes to wrap my coil then. I was thinking thicker then0.5 10 I was thinking what’s best as per pic yes

1
Nikola TeSlaa
Nikola TeSlaa

8 months ago

hello so my teacher said to bulid a tesla coil and i did it worked perfectly un till it made a hole on the wall can u tell me what i just did?

0
kohlemanoj78
kohlemanoj78

Question 8 months ago

Can we increase the frequency than range was increse

0
kohlemanoj78
kohlemanoj78

Question 8 months ago

Pize sir Macke video on YouTube clarlay and tell in DTL
I was quricy to understand it

1
And_777
And_777

10 months ago

Can anyone explain the wiring? I’m stuck at this part because I don’t understand the diagram.

0
phr256
phr256

Reply 9 months ago

In the circuit, a neon sign transformer(nst) is used, its output will charge up the capacitors which will be almost instantaneous. However, the time taken for that will determine your frequency(I think). When it is completely charged the output will travel through the spark gap and activate the primary coil. Which will then induce the secondary coil and cause the spark or whatever. This will be taking time similar to the time taken for the capacitors to be charged.

0
jumpup_dnb_dj
jumpup_dnb_dj

Question 11 months ago

Doesn’t your power supply have a gfi?

0
prajapatiharsh285
prajapatiharsh285

Question 1 year ago

Can you plsease tell me the capacity of capacitor?