Illuminate Lightbulbs Wirelessly: DIY Slayer Exciter





Introduction: Illuminate Lightbulbs Wirelessly: DIY Slayer Exciter

Have you ever wanted to be able to control the powers of wireless electricity? Have you ever wanted to build something that can light CFL bulbs from your hand? If so, then this is the perfect instructable for you. In this instructable, I will show you how to build a device called a slayer exciter. The video below will accompany this instructable with a visual demonstration of how it works.

Lets get started!

Step 1: How It Works

A slayer exciter is basically an oscillator that has a frequency based on the LC tank circuit formed by the secondary coil and the parasitic capacitance of the top load. So now to how this circuit works. First, when power is applied to the circuit, the current flows into the base of the transistor, turning it on. When the transistor turns on, it lets power flow through the primary coil. This induces a current into the secondary coil, which flows into the base of the transistor, turning it off. When the transistor turns off, the magnetic field collapses letting current flow back into the base of the transistor from the resistor. This cycle repeats many times a second. Think of this circuit as a swing, if you push somebody an a swing, they will swing forward and backwards and oscillate. Every time you push the swing, it oscillates, but you have to push it at the right time, or it will loose energy. The circuit functions like the person pushing the swing. The transistor "pushes" the secondary coil with a magnetic field at the exact right time. This circuit oscillates at about 398 kilocycles. The constantly expanding and collapsing field creates a powerful RF field around the exciter. This causes the electrons in the CFL to bounce around and strike the phosphors in the glass, lighting the bulb. It creates high voltage because of the turn ratio of the primary to secondary coil. Now to actually building the slayer exciter.

Step 2: Materials

For this project, you will need a few different tools and materials.

You will need:

  • A 600-1200 turn secondary coil (Refer to my other instructable)
  • 20-26 gauge wire
  • 30k Resistor
  • NPN Transistor (Most NPN transistors in a TO-22 case will work)
  • 1n4001 diode
  • Solder
  • Cardboard
  • Pie tin


  • Different types of lightbulbs (Fluorescent, Xenon, Incadescent, Neon)

Step 3: Tools

For this project you will need a few tools:

  • Soldering Iron
  • Wire strippers
  • Wire Cutters
  • 18 Volt power supply
  • Hot glue gun

Step 4: The Primary Coil

The first step of this project is to create the primary coil. I did this by wrapping speaker wire 4 times around a piece of cardboard rolled into a cylinder. I then glued my secondary coil to a piece of plywood. You can experiment with different amounts of wire turns to accomplish the most efficient coil.

Step 5: The Top Load

The top load of the slayer exciter is what gives the coil the parasitic capacitance needed to oscillate. I used a pie tin, but you can use almost any piece of metal without any sharp edges. Sharp edges cause unwanted discharge of electrons into the air. You then need to place the top load on top of the coil and connect it to the top wire of the secondary. You can experiment with different top load sizes to obtain optimum performance.

Step 6: Building the Circuit

The circuit is what causes the slayer exciter to oscillate. To build this, I used point to point soldering. I used this method because there are only a limited amount of components needed for this project, so it would have been a waste to solder it on a perf-board. Another option for this step is to build this on a breadboard. Make sure to connect all of the components in the same way shown on the schematic. Connect the bottom end of the secondary to the base. You also need to connect the bottom of the primary coil to the power supply, otherwise the circuit will not oscillate. After this step is done, your circuit should work.

Step 7: It Works!

Once the circuit is build, you can test the slayer exciter by plugging it in to a power supply and turning it on. It should produce a waveform on an oscilloscope, and light any fluorescent bulb nearby the secondary coil. My setup is in the picture above.

Step 8: Final Product

This coil is able to light a wide variety of lights and make a cool spark, as you can see in the pictures above. Just by holding a screwdriver to the top load, I was able to draw a spark. You can also draw a spark with your hand, the voltage does not have enough amperage to electrocute you, but the sparks can burn your skin. This project is a good demonstration of what a tesla coil can do without all the expensive parts.

Thanks for reading and good luck building!

Disclaimer: This device produces potentially harmful voltages. It also produces magnetic fields that can harm and interfere with electronic devices nearby.

Circuits Contest 2016

Runner Up in the
Circuits Contest 2016



    • Creative Misuse Contest

      Creative Misuse Contest
    • Clocks Contest

      Clocks Contest
    • Oil Contest

      Oil Contest

    38 Discussions

    I made it and it worked with a 12 v battery .But the coil broke the battery because it used up more than 20 amps at a time .Any ideas about what i did wrong , or what i can do to power it with any other way ?

    Very well explained!

    Can I use a 2A2222 NPN transistor for making the slayer exciter?


    I'm not sure I understand the comment. I thought Tanner built a Tesla coil to create the oscillating EM field to drive his fluorescent? Did I miss something here?

    He did, I just realised he called it something else after I commented. It is a tesla coil.

    All in all that is a great instructable. I love seeing people make tesla coils, because Nikola Tesla was an amazing man and inventor, who died friendless and hated. Only later did they discover how much he changed the world. Great job! I have never seen one made without capacitors at the bottom, to regulate to power flow and help create the magnetic field that makes the top wire broadcast energy. So this was a fresh and new idea to me. Thanks!

    I love these wireless ideas and experiments, nice job!

    However, when we do things wirelessly we pay a price. In general it costs more in power, and thus money, to do things wirelessly than it does with wires. This is mostly because of the inverse square law of power/signal transmission but also because the power goes everywhere and not just to the device that is using it.

    From the photo the power supply is running at 18.41 Volts and supplying 3.35 amps for a power of 61.67 Watts and a 60W equivalent CFL bulb generally takes about 15 Watts so for this one build we're back to using over 60W of power. This is assuming that the power supply pictured is in fact running your power transmitter.

    Now, if this device can power five or more 15W CFL bulbs we'll be saving energy, using less power than plugging in five 15W CFL bulbs. Again assuming we'd only need the 61.67 Watt power transmitter.

    So first, how much power are you using to get that one bulb to light?

    What power rating is the CFL bulb you're using?

    Is the light produced at the same level as with a direct electrical connection? If not, is it brighter or dimmer and by what amount?

    Have you experimented to see how many bulbs and at what distance this works?

    Again, very nice I love it!

    1 reply

    These are good questions. I wonder how much power loss there is and whether you can build a heater this way.

    What if I wanted to make use of some otherwise dead 48" florescent tubes mounted around a 48" long tesla coil.

    I wonder if you can direct the EM field in one direction to optimize lighting.

    Has anyone been able to do calculations to see if it makes economic sense to build and use one of these?

    I hunted under a power Grid in Texas. I had a box stand on the edge of the right of way. I use to keep a fluorescent tube in the stand. I hooked a coil of wire to the tube to light it. The energy was free to me.

    1 reply


    If I lived next to one of these, I'd put up Faraday cage around the house, then power with a flatbed mounted humongous Tesla coil sitting under the right of way connected to my house.

    Great science project. Although due to the high voltage and extreme electromagnetic radiation it has no commercial use and the FCC may want you to put it in a faraday cage.

    maybe you could do wireless charging, with a phone and that hidden, which you could control through your pone.....would be a nice party trick

    Great presentation and explanation. Well done!

    Not bad, although the transistor has to have a transition frequency of at least 1.5Mhz though. Also, the biasing resistor value may need to be changed according to the Hfe of the transistor.

    You can use a ruler for that if the coil has only one layer. Just count how many turns are in a centimeter and multiply it with the length of the coil.


    1 year ago

    if I'm guessing right, I can light up a fused CFL bulb too?!

    but you have to push it at the right time, or it will LOSE energy

    This is cool to play with but, you don't get something for nothing.. It takes more energy to light the bulb wirelessly that just plugging it into the wall..