Simple “Slayer Exciter” Tesla Coil

This is a simple tesla coil that can do all the things a normal one can. DISCLAIMER: I am not responsible for anything you do with this coil or what may be harmed by it, be safe. This tesla coil is perfect to learn about the principles of oscillation, frequency, and wireless power transfer. Inspired by: How-ToDo

1. 6+ inches of 1.5 inch plastic pipe
2. Large spool of 32+ AWG wire
3. Small length of 10-14 AWG wire
4. 13009 NPN Transistor
5. Small heatsink for transistor
6. 60 K Potentiometer
7. DC power supply 9-20 volts
8. Soldering iron + solder
9. 180 ohm resistor
10. Insulating enclosure for coil

The most tedious step of this entire project is winding the secondary. You have to grab some 36 AWG wire and wrap it around 6 inches of plastic pipe without crossing or tangling it(very much). I recommend using tape to save your spot.

This is easier; wind the bigger wire around the secondary coil 3-5 times and tape.

Before you operate this circuit, you should be able to understand how to build it just with the circuit diagram. Not much else to say, read the diagram, solder the connection's, and don’t use large lengths of wire. Just solder together. Don’t forget to burn of the insulation at the ends of the secondary or else it won’t work!!!

This coil can do the tricks any others can! More for learning than power.

Shout out to How-ToDo, I recommend checking out his tutorial (I used his circuit diagram).

1. Wrong or dead transistor

What happens: Nothing oscillates, or it instantly overheats.

Check: Transistor may be installed backwards or already damaged.

Fix (safe check): Verify part number + pinout against the datasheet and test it with a multimeter diode mode.

2. No proper power supply current

What happens: Weak output or no oscillation.

Check: Supply voltage drops hard when connected.

Fix: Make sure your supply can actually deliver the current the circuit demands (Slayer exciters are very current-hungry).

3. Primary coil wired wrong

What happens: No oscillation or very weak spark.

Check: Coil direction or connection points may be reversed.

Fix: Re-check continuity and that the coil is actually connected where the circuit expects feedback.

4. Feedback winding issues

What happens: Circuit refuses to self-oscillate.

Check: Secondary/feedback coil not producing usable signal.

Fix: Ensure correct orientation and that windings aren’t shorted or swapped.

5. Bad grounding / floating reference

What happens: Random behavior or total silence.

Check: Circuit reference isn’t stable.

Fix: Ensure a solid common ground between power supply and driver.

6. Transistor overheating instantly

What happens: Works for a second then dies.

Check: No heatsink or too much current draw.

Fix: Reduce stress conditions and confirm the coil isn’t effectively shorting the output.

7. Oscillation frequency mismatch

What happens: No spark or very weak output.

Check: Coil and transistor can’t sustain resonance.

Fix: Adjust coil geometry or feedback coupling (small physical changes matter a lot).

8. Shorted secondary coil

What happens: No output, heavy current draw.

Check: Continuity test shows unintended paths between turns.

Fix: Inspect for damaged insulation or overlapping wire contact.

9. Poor or loose connections

What happens: Intermittent operation or total failure.

Check: Works only when wires are moved.

Fix: Rebuild connections solidly (breadboards are especially unreliable here).

10. EMI / layout instability

What happens: Random startup, shutdown, or instability.

Check: Circuit behaves differently when moved.

Fix: Keep wiring short and tight; these circuits are extremely sensitive to layout.

Keep in mind these circuits can create electromagnetic interference and could damage electronics!!!