Tesla coil not working ? | Tesla coil

Many students out there reach me through emails or social media channel that they have made a tesla coil ( slayer excitor ) using any popular circuit but that’s not working. Here are 5 common mistakes that I found followed by my suggestions on them.

The five common mistakes are –

  1. Low Battery
  2. Faulty Transistor
  3. Winding Of Coils
  4. Top Load
  5. Proper Checking Of Tesla Coil

First of all make sure that you have made all your connections according to the circuit diagram.

Low battery

  • If your tesla coil is not working and you are using battery as a power source then the first thing you should check is battery’s voltage.it should be 8V or above.
  • I suggest you to use transformer or SMPS ( Switch Mode Power Supply ) as power supply for tesla coil.

Faulty Transistor

  • Semiconductor devices like transistor blow up very easily if mishandled. You can check it in multi meter or simply replace it. Transistors getting warm is normal but it should not overheat.
  • For high power input use any of these listed transistor with a heat sink.
    • 2n2222a ( for 9v Battery )
    • Tip31c
    • Tip35c
    • Irfp260
    • Irfp460

Winding of coils

  • Wind the coils as close as possible and do not overlap.
  • Make sure that the direction of primary winding and secondary winding are opposite to one another. You can simply invert the end of primary coil that is connected to circuit.
  • Make sure to scratch off the insulation of secondary wire ( magnet wire ) when the lower end is attached to circuit or when the upper end is attached to top load.

Top load

  • Students usually use heavy metals for top load.
  • If you are using a very lower power source such as battery then make sure you use a very lite weight top load. Make it using aluminium foil. Take a ping pong ball and wrap it with aluminium foil. Ensure the surface to be smooth as possible.

Proper checking of tesla coil

  • Students to admire the working of their coil mostly use LED’s in excitement but that doesn’t glow until your tesla coil is powerful.
  • Many time it happens that the fluorescent lamp that you use is itself leaked or dead. I suggest you to use new lamps or check by bringing electric tester near the top load.
  • Small neon bulbs glow beautifully.

Wire gauge and winding suggestion

  1. Suggested wire gauge
  • 28 to 38 gauge
  1. Number of turns in primary
  • 2 to 5 turns
  1. Number of turns in secondary
  • 300 to 3000 turns



Akash Sharma

For more clarity watch my YouTube video.

If you face any other problem, do comment, I will try to solve it.

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9 thoughts on “Tesla coil not working ? | Tesla coil”

  1. Thanks for this Website and the YouTube Video but, I checked every detail this told me, and my tesla coil did not have that problem. So what is it? My tesla coil’s primary coil is very thin, but not as thin as the secondary coil. Its about twice the diameter of my secondary coil do it should work just fine. But as you know… it does not work. so if you could help me with this that would be great. Thank you!

  2. Thanks for the info ,but it still doesn’t work

    I am making a Slayer exciter Tesla coil , 9V battery ,DC-DC voltage doubler ,TIP31C transistor , and a 47k ohm resistor,(no diodes or led),666 turns on secondary ,3-4 turns on primary .
    My calculated output voltage was 5000v ,but I’m not even getting an arc at the end
    Also,for some reason my transistor(tip31c) is heating up

    Please help me fix it
    I only have 12 hours 🙁


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