Tesla coil is a radio frequency oscillator that drives an air-core double-tuned resonant transformer to produce high voltages at low currents.Tesla's original circuits as well as most modern coils use a simple spark gap to excite oscillations in the tuned transformer. More sophisticated designs use transistor or thyristor switches oscillators to drive the resonant transformer.
Miniature Tesla coil also does a same work but it does not produce as much high voltages.
Now I am going to instruct how to make a miniature tesal coil with less number of components.
Lets Get Started..
Step 1: Components Required
22 gauge magnetic Copper wire - 30 cm [Banggood]
28 gauge magnetic Copper wire - 10 m [Banggood]
PVC Pipe [Diameter - 2cm ; Length 9cm]
Switch -1 [Banggood]
2N2222A Transistor - 1 [Banggood]
22K Ohm Resistor - 1 [Banggood]
9V Battery and Clip - 1 [Banggood]
Cardboard Sheet [10 x 10 cm] - 1
Step 2: Circuiting
1. Take pvc pipe and winde 300-400 turns of 28G copper wire.[Primary coil]
2. Apply tape at bottom and winde 4-5 turns of 22G copper wire [Secondary coil].
3. Now remove enamel of copper wires at end.
4. Solder 22k ohm resistor to the base of 2n2222 transistor.
5. Solder bottom end wire of primary coil to base.
6. Solder one end of secondary coil to collector.
7.Solder Positive terminal of battery clip to Switch and negative terminal to emitter pin.
8. Now solder another end of secondary coil and another pin of switch to the free end of 22k resistor.
9. Leave the top end wire of primary coil free in air.
Circuit and Datasheets attached.