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Simple Tesla Coil with 2N2222

In this electronics project, we will make a simple Tesla coil circuit with a 2n2222 NPN transistor. The coolest thing about this project is its simplicity. This is one of the simplest and easiest circuit design, with just a few simple parts, you'll be creating your own mini tesla coil. It can transfer wireless electrical power to the CFL in no time. Let's make it!

Components List

The following components are needed for this project.

  1. 2n2222 NPN Transistor (1 pcs).
  2. 22KΩ 1W Resistor (1 pcs).
  3. 0.02-0.25mm Insulated Copper Wire (as per required).
  4. Wire (as per required).
  5. PVC Pipe (1 pcs).
  6. PCB (1 pcs).
  7. 3.7-9V Battery (1 pcs).

Tools needed:
  • Soldering Kits.
  • Scissors/Knife.

Tesla coil Circuit diagram

Schematic of the Tesla coil circuit shown below. You can follow the same.

Schematic of Simple tesla coil circuit with 2n2222
Figure 1: Simple tesla coil circuit diagram.

Mini tesla coil circuit with 2n2222, Modified
Figure 2: Mini tesla coil circuit Diagram [Modified].

Circuit working explanation

As you can see [Figure 1], when the circuit is turning ON, 22KΩ resistor drives the base of the 2n2222 transistor (you can use 2N5550 or similar regular NPN with >50V VCE and >60 hFE).

This circuit can be powered by 3.7V to 9V D.C. supply (here I used 3.7V lithium cell).

After the transistor turns ON and drives current into the primary coil (3 turns) of the transformer, the current is limited by the limited available base current.

The created magnetic field drives the secondary coil (275 turns) of the transformer and generates a voltage.

This voltage wants to grow large, but the small amount of stray capacitance rises on the output end and, so the voltage return on the other end of the transformer goes down through the air, which pulls the base of the transistor low.

This phenomenon causes the transistor turns OFF, and so the magnetic field starts to reduce.

The base voltage rises again, and the transistor turns on, and this process goes on and on very fast.

Demo & Testing - Simple Tesla coil with 2N2222

Below, you can see the simple tesla coil in action.

Simple Tesla Coil in action
As you can see, the Tesla coil transfers wireless electrical power to the CFL.

Do you know how does a CFL bulb near Tesla coil glow? - The secondary coil in the Tesla coil radiates electromagnetic waves in the surroundings, at high voltages. When a CFL or neon lamp comes near it, the radiation makes the electrons in the internal materials (gases) of the lamp, which oscillate, and they emit photons.


  1. Thank you so much for the explanation and the diagrams.
    My question is: on the modified circuit diagram, what is the function of the 1uf capacitor?
    Thank you again.

  2. What is it that have you used instead of a toroid?

  3. Does it produces sparks with your modified circuit ?

    1. I belive for the sparks you would have to use a more powerful transistor. A 2n2222a NPN transistor can theoretically can make sparks with a higher voltage input, but the transistor would heat up very fast and fail short or open. But the transistor has a thing where if the voltage across the emitter and collector is higher than the breakdown voltage, the transistor will allow current to flow through them despite there being no current flowing through the base and emitter. A D1047 or TIP41c or TIP31c transistor would be suitable for the high voltages. Though be warned, the transistors mention above have a different pin configuration than the 2n2222 or the 2n2222a.

  4. this is working with 10k
    3 turns and 300 wds

  5. I put everything but why my Tesla coil not working ( also my secondary coil is 300turn ,is it okay ?)


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