My Tesla coil is not working

Question

I made a Tesla coil, but it doesn't not work. I used this circuit:

I used 200 turns for the primary coil with 0.5 mm wire and 5 turns for the secondary coil with 1 mm wire on a wooden rod.

Back to the circuit: I don't have a 2N2222A transistor, so I used a TESLA T91 KF 508 321.

I think the problem is in the transistor, but I am not sure. Can you tell me what I am doing wrong? Do I have to buy the right transistor?

11.8.2022:

I made another Tesla coil with a 2N2222A (yes, I bought it) and it still doesn't work!

The small coil has 2-3 turns 1 mm and the big coil 100 turns 0.5 mm.

I used a 9 V battery and when I started it, the transistor became very hot (I think I didn't destroy it, beacuse when I cooled it down and started it, it started and was still showing the diagnostic (It's down)). I used my multimeter.

Here are my diagnostics:

On the small coil I can measure some voltage, but only in AC multimeter mode.

On the big coil isn't any plasma and it's not turning on my LED. I even tried to touch it and still nothing.

My 9 V battery has 8 V, 0.3 A I think

So, am I cursed or what? I don't have an oscillator, but I heard about a program that lets you connect a PC to the circuit and it will show you the frequency.

Answer 1

Made with microcap v12. All FREE.
NB: this circuit is very "weird". Not simple to do it "working".

Here is the behavior for this configuration ...
Note that "coupling" is very of "some importance".
Note also the "protection" circuit added for the base "breakdown".

Here is an expanded view.

Note that 2N2222 should not be ok for this task (Ic max, Pcmax).

Here is the behavior with a power transistor. Parasitic capacitors added.

Answer 2

A few things, for a lower power design the smaller coil would typically be more tightly wound, and it would be located closer to or over the bottom edge of (but still well insulated from) the larger coil. (See other internet examples such as: https://www.youtube.com/watch?v=xQoXMQ4js6k). Your coil assembly as shown would likely have a reduced coupling between the coils. What you label as the primary and secondary coils would typically be reversed, you would normally drive the primary side of a transformer, (but from your picture it looks to be connected correctly). Some of the specifications for a Tesla KF508 transistor (from Ebay) are as good as a 2N2222, however the max Ic is only listed as 500ma (a 2N2222 has a max Ic of 800ma). So that gives a higher chance of burning out the KF508 transistor.

Many example circuits do use a 2N2222 and a 9v transistor battery for a Tesla coil circuit. In most cases that should work well enough, (though the circuit from Antonio51 looks much better.)

A good 9v battery might provide a maximum of about 1A for a short time, that could potentially burn out the 2N2222 (or a KF508) if it were sustained or if the circuit failed to oscillate. Using a 12v high current supply there would be an even higher chance of burning out the transistor. I noticed that the Tesla circuit design from "Instructables" has a circuit diagram with a 12v supply but actually in the final assembly uses only a 9v battery.

A few other tesla coil examples use a higher current power tab transistor, (eg. TIP41, BD243C).