TESLAS PANCAKE COIL CIRCUIT SIMPLIFIED ???

[magnetman12003]

Below is a video showing two tesla pancake coils and a very simple circuit that powers one of the coils and feeds the other coil.
My question is just how can I get rid of that 5 watt power robbing resistor and make the circuit very efficient and still keep it simple?
A nice diagram would be very helpful.

https://www.youtube.com/watch?v=4UmVLfFNx7U

All help appreciated.

[Reiyuki]

You're already down to a resistor, transistor, and a coil; it's gonna be hard to get much simpler than that.

That said, you could try using a small second coil in the field to gate the transistor:
https://upload.wikimedia.org/wikipedia/commons/thumb/4/4c/FET_Armstrong_oscillator.svg/220px-FET_Armstrong_oscillator.svg.png
(A second small bifilar pancake could take the place of L1 and C in the diagram.)
   Start with a low number of turns though and use a scope or LED's to gauge the power level before you hook it to the transistor.  The gate is more sensitive and might get fried if it takes a hard hit.  Maybe put the resistor in series with this extra coil and vary the extra coil distance to vary the pulses.

You could also try experimenting with other types of transistors (bipolar transistor, switching transistor, mosfet, etc).  You might get better/worse power and efficiency with certain types of transistors.


For a single component but not much control, you could also try making a relay oscillator and experiment with that:
https://www.circuitlab.com/circuit/87bane/screenshot/540x405/


hope that helps, have fun