The video describes how to make a Tesla coil with the help of only a few components:
     - Fluorescent lamp ballast (one or two , 370mA-740mA)
     - UF5408 or similar ultrafast diode
     - 1 microF/400v MKP capacitor
     - IRFP250 or similar Mosfet Transistor
     - 12v/1w Zener diodes   - 2pcs
     - Potentiometer 10 kOhm
     - 12 kOhm 1/2w resistor
     - coils (primary and secundary) 

Characteristic of this design is that it does not use expensive elements like transformers and capacitors, it is easy to make and produces a relatively large spark of 5 cm and more. As you can see in the video, I also experimented with a light bulb instead of a ballast, but for this purpose the light bulb needs to be 200W or more. The primary coil contains 5 windings of insulated wire with a cross section of 2.5 mm^2 , and the secondary coil contains 1000 windings of wire with a cross section of 0.15 mm^2. With the help of the 10km potentiometer, the oscillation threshold of the primary circuit is adjusted as well as the frequency, and thus the size of the spark.

   Schematic diagram is very simple and is presented below:

      And a very important note: The device is powered directly on 200V so you must adhere to all safety rules.