Introduction: Slayer Exciter Circuit (Poor Man's Tesla Coil)

About: I love making and breaking electronics.

Hello everyone!! Today I am going to show you how to make a Slayer Exciter Circuit, which works almost like a Tesla Coil. So what is a Slayer Exciter? It is a self-tuning and self-resonating Tesla Coil. Tesla Coil is an electrical Resonant Transformer Circuit that basically produces sparks, giant sparks, huge amount of voltage, and can destroy or turn on electronics at a distance. Whereas the Tesla coil depends on capacitors, spark gaps, multiple coils to resonate and tune the circuit and adjust the voltage, a slayer exciter resonates and tunes itself without any complicated circuitry . It's an extremely simple circuit, which is why it is really popular among electronic hobbyists or beginners like me. Plus if you are trying to learn how Tesla Coils work, building and understanding how Slayer Exciters work can be helpful.


Now time for some warnings, cause why not.

This is not a perfect wireless transmission device which you could use to charge your electronics devices. It isn't even really useful in real life uses. But that is not point of this build, in fact the main point of the build is to familiarize with the basics of simple electronics. Just leaving this as a warning, because a lot of people raise their expectations too high to be disappointed too much with anything I make or show. Also I am an 11th grader, not a Graduate in electronics major, so I am bound to make mistakes, and I would definitely be happy if you help me correct them. Anyway now that the warnings are laid forth, let's keep moving.


The circuit is build based on the instructions provided by a youtuber named Ludic Science. Pay him a visit for more info, or more interesting circuits.

The instructable is divided into many short steps to make sure it is super simple to follow. The steps are divided in the following order:

1) Step 1: Watch Video!

2) Step 2: Circuit schematic & breadboard diagram.

3) Step 3: Materials.

4) Step 4-7: Making the coils.

5)Step 8-14: Making the circuit on a breadboard.

6) Step 18-22 : How does it work?

7) Step 23& 24: Troubleshooting tips and finishing words.

Alright, lets get to the build!!

Step 1: Watch the Video!!

Most of the things in the video is covered in this instructable, but if you prefer watching videos over reading instruction then watch my video! I desperately hope it will be helpful to you in some way. Also watching the video on youtube will increase my youtube views and maybe my funds for my future projects, so give it a go!

Step 2: Circuit Schematic

So here's the schematic of the circuit. I hope it could be a great aid in making the circuit, because it is really difficult to individually instruct on where to connect the wires. So try to follow the schematic if you can.

If you are having trouble understanding the schematic or its parts, then go to step 18.

Step 3: Gather the Materials!

To make it on a breadboard you will need the following things:

1) 22K Ω Resistor.

2) 2N2222 NPN Transistor. ( Any NPN transistor should work. The only problem is that if the transistor is not created to handle high current, then the transistor will heat up and melt in the circuit. So pick an NPN transistor with high current rating.)

3) Red or green LED.

4) 9 V battery & clip.

5) A plastic tube with diameter of 1-1.5 inches.

6) 26-32 gauge magnet wire ( copper wire with thin insulation). The smaller the gauge the thicker the wire is.

7) Thick insulated copper wire.

8) Breadboard.

And most importantly you will need patience. We will be coiling wires, and we be coiling for quite a while. Patience is the key, remember it.

Step 4: Let's Start Coiling! (1 of 3)

First take a plastic cylinder that is about 1-1.5 inch in diameter. It should be hollow. AND IT CAN NEVER BE ANY METAL CYLINDER. Okay start by poking a hole at the side near one of the ends of tube.

Take the 26-32 gauge wire, and pass it through the hole in the tube. Make sure to pass at least 3-4 inches of the wire through the hole. Then use tape or glue to secure the wire that is on the tube. Now start winding coils on the tube.

Coil the wire about 250- 325 times.

Step 5: Coiling Is a Pain (2 of 3)

After a few turns try to use glue or tape or something to keep the wires in place. I used nail polish to keep the wire in place. It is really important to make the coil NEAT. Do not overlap any turns, or leave gaps between turns. The glue or nail polish will be like a checkpoint so that you don't have to restart from the beginning if you mess up somewhere. It is a test of patience, I accidentally overlapped wires and it came loose, but thanks to the nail polish I didn't have to start from the beginning.

Step 6: No Pain No Gain(3 of 3)

So after coiling 250-325 times, leave about at least 3-4 inches in the end, and cut the wire. Now poke another hole in the tube, and pass the end of the wire through it. Use tape or glue to secure the wire in place. So now you will have a coil of 250-325 turns around a plastic tube, with 2 ends coming out of two sides. You can finally take a rest from coiling!

This is our secondary coil.

Step 7: Another Coiling Step.

Take a thick insulated wire, and wrap it 3-5 times around the plastic tube, in the OPPOSITE direction as the secondary coil. This is extremely important that it be wrapped in the opposite direction as the previous one. Now use glue or tape to keep it in place.

This is our primary coil.

Alright, now you are done with coiling. No more coiling.

Step 8: Breadboarding! (1 of 7)

Now let's start the breadboarding. Place a breadboard and place the transistor in the middle with the flat side facing you.

Note: If I tell you to attach a lead of one component to another component on the breadboard, just place the lead of the component in the same row as the other component. Since the horizontal rows in breadboard are connected together, placing two leads in the same row will create a contact between them, allowing electricity to flow.

If you do not know the polarity of the components, they will be mentioned in the step about how the circuit works.

Step 9: Breadboarding (2 of 7)

Now attach the 22 Kilo Ohm Resistor to the Base of the transistor.

Step 10: Breadboarding (3 of 7)

Now attach the negative side of the LED to the Base of the transistor.

Step 11: Breadboarding (4 of 7)

Attach a jumper wire from the Emitter of the transistor to the Positive side of the LED.

Step 12: Breadboarding (5 of 7)

Attach the Black wire from the battery clip to the Positive side of the LED. Attach the RED wire of the battery clip to the free end of the Resistor.

Step 13: Breadboarding (6 of 7)

Now take the wires from the primary coil, and attach one end to Collector of the transistor, and the other end to the Red wire from the battery clip.

Step 14: Breadboarding (7 of 7)

Now attach one of the ends from the Primary Coil to the Base of the transistor.

We are done with the breadboarding!! Simple, right?

If you want you could solder it, but I was too exhausted to solder.

Step 15: Let's Make It Look Acceptable (1 of 2)

Place the breadboard and the coil on top of a carboard box, wood box, metal plate or whatever makes it look like a completed project.

Step 16: Let's Make It Look Acceptable (2 of 2)

Now take a piece of aluminium foil and roll it to a ball. Then attach the free wire from the Primary coil to the aluminium ball. Place the ball on top of the tube.

Step 17: Now Let's Test It Out!!

Connect the 9V battery to the battery clip. Now bring a CFL light bulb close to the aluminium ball or the coil, and it should light up! Our tiny circuit (excluding the size of the coil) is working!! Do not keep the circuit on for too long, otherwise the transistor will blow up. If you notice any smoke coming from the transistor, disconnect the battery IMMEDIATELY.

Note: Please ignore the messy background and table.

Step 18: How Does It Work? (1 of 5)

Let's familiarize ourselves with the components.

Transistor: A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit. (Wikipedia). Our transistor is Bipolar Junction(BJT) , NPN type, which means a P-layer of semiconductor is sandwiched between two N-layer semi conductors. The BJT transistor that we are using has three pins, when the flat side is facing you, from left to right the pins are Emitter, Base, Collector.

The Emitter and Collector is like a variable resistor, with the knob to change the resistance being the Base. Usually the transistor stays in its Maximum resistance state, so the resistance between the collector and emitter of the transistor would be too high for any amount of electricity to pass through. But when there's a voltage at the base of the transistor the resistance between the emitter and collector decreases to allow electricity to flow through. So the base is like a switch, if you turn on the switch by applying a voltage at the base, current can flow through the collector and emitter. Now an NPN transistor requires a positive voltage at the base to go into least resistance mode, while

a negative voltage is needed if it is a PNP transistor.

LED: Light Emitting Diode, known as LED, are diodes that produce light when current passes through them. The smaller lead of the LED is negative. On the schematic, the LED looks like an Arrow hitting a wall, with two more arrows pointing outward. The side with the arrow is the + side.

Resistor: Now a resistor is simpler since it has no poles. You could connect it either way. A resistor is just any material that resists flow of electricity to a certain degree. The resistance of a resistor is shown through the color bands on the resistor. Use this to calculate the resistance of a resistor of unknown value:

Note: These two images aren't mine.

Step 19: How Does It Work? (2 of 5)

Alright, I will be using strictly Conventional Current to talk about this circuit. It will be mostly analogies, not equations or details. If anything is mistakes, please help me correct it.

So let's go one step at a time. So here we have a circuit, the + of the battery connects to - , with a transistor in between. Since there is no voltage at the base the transistor has maximum resistance between collector and emitter. So current can't flow through the transistor.

Step 20: How Does It Work? (3 of 5)

Then we attached a resistor from positive of the battery to transistor's base. Electricity can flow through the base to the emitter to the negative of the battery.

Step 21: How Does It Work? (4 of 5)

Then we added a primary coil of 3-5 turns. Current flows through that, and the wire produces a magnetic field. ( Flowing charges produce magnetic field.)

Step 22: How Does It Work? (5 of 5)

Then we attached a secondary coil to the base of the transistor, and then we attached LED between base of transistor to the negative side of the battery.

Since the primary coil produced a magnetic field, it induces electricity in the secondary coil. (Conductors moving through a uniform magnetic field, or stationary within a changing magnetic field, will have currents induced within them.) When current flows through the secondary to the top, it creates a 'vacuum' of charge. To fill that vacuum, current flows through the resistor up the secondary coil. Current is also pulled through the LED to the secondary coil, lighting up the LED a few times. Electricity tends to take the easiest path or the path with least resistance, so instead of having to go through the 22K resistor to the base, it mostly goes through the LED to the Secondary Coil. So in the end, very little current can go to the base of the transistor, and the 'switch' turns off, and the resistance between collector and emitter goes back to its maximum state. The process restarts, and the circuit keeps turning on and off by itself, really rapidly.

Now the primary coil has only 3-5 turns, and the secondary coil has 250-325 turns. It works like a transformer, the 9 V in the primary coil is stepped up to hundreds of volts in the secondary coil due to the high ratio between secondary coil winding to primary coil winding. This high voltage is enough to excite the fluorescent materials in the CFL bulb.

Our circuit also has a capacitor, a parasitic capacitor, which is also known as stray capacitance since its not intentionally created, it's just there. This capacitor connects between secondary coil to ground. This means that secondary coil isn't open, current can flow through it.

If you thought my explanation was horrible, then check out this instructable which has extremely detailed and well described explanation of the circuit : .

Step 23: Troubleshooting Tips

So in the next few paragraphs I will try to solve a few of the problems you might be facing while making it.


Solution: Calm down because I don't have either the patience or the sadistic nature in me to make someone waste hours of their youth to make a fake circuit. Let's slow down and get along with the rest of the problems. ( This happened to me countless times on youtube, people blaming me for their circuit not working.)

Problem 2: The Circuit doesn't work, would you help me fix it?

Solution: This is a better way to express your opinions and needs. Alright the circuit may not be working due to several reason. Did you make your connections properly according to the schematic? Check it. Did you properly remove the insulation from the ends of the coil? Because a lot of times people don't do it and magically their circuit doesn't work. Did you insert the transistor in the right orientation? Check to make sure the flat side is facing you, then the pin layout will be Emitter , Base, Collector from left to right . Did you use an NPN transistor? If you use PNP you will have to change the layout.

Problem 3: My transistor heats up too much!

Try using a heat sink to reduce the heating issue. Or use a transistor with higher current rating. Or try putting TWO transistor in parallel, this will divide the current, and reduce heating issue. Or use a resistor of higher value.

Problem 4: My LED doesn't light up.

Solution: Its alright if the LED doesn't light up, mine didn't either.

Problem 5: It doesn't light up the CFL.

Solution: Try flipping the wires from the primary coil connection.

Problem 6: It still doesn't work.

Solution: Life is difficult, and it is okay to accept defeat sometimes.

Step 24: Finishing Words

Alright I am almost running out of fumes.

I hope you guys found this circuit interesting and maybe want to try recreate it too. If so, then my writing this instructable was successful. Once again I am an amateur in electronics, and definitely could make mistakes. I would appreciate anyone fixing the mistakes for me. Help me improve the explanation of how this circuit works if you can. Thank you for reading and hope you have a good day!