Howdy, I’m Dayton Aardema. Today I’m going to build a tesla coil design called a slayer exciter. Here you can see a schematic for the slayer exciter. It has a power source, a resistor, a transistor, a primary and secondary coil, and the capacitor symbol at the top of the secondary just represents a small capacitance with air.
As current starts flowing through this circuit, it’ll diverge before the resistor. But it can’t go through the primary coil since the base of the transistor is not powered. The transistor is acting like an open switch; what will happen instead is that current will flow to the base of the transistor opening the gate and allowing current to flow through the primary to ground.
As this happens, the primary coil will create an electromagnetic field which will be induced into the secondary creating a current in the opposite direction. This will cancel out the current going to the base of the transistor causing the electromagnetic field on the primary to collapse and the entire process to start over.
The design of the slayer exciter need a resistor, it can range anywhere between 10 thousand and 100 k ohms; these ones here are 47 k ohm resistors. If you buy them in bulk, you can get them a lot cheaper than if you just buy a few.
So there’s a pack of a hundred. This is magnetic enameled copper wire. It’s what I’m going to use to wind my secondary coil. … It’s going to be this PVC pipe which I’m going to wrap the copper wire around.
I’m going to use this smaller piece of PVC to wrap my primary since it fits nicely around the secondary coil. You should also be sure to have some rated wire on hand. The integral part of the design are these transistors: TIP31C transistors.
They will oscillate which will provide the circuit with an alternating current. In order to supply power, you should use at the minimum a nine-volt battery. However, I personally prefer my power supply.
At long last, I have finished winding my primary and secondary coils. The primary coil has about three and a half winds and the secondary has: I estimated it around 750. I was also sure to use sandpaper on either terminal end of my wire so I can get a good connection when I solder.
I’ll test that now with my multimeter… ..I’m going to measure resistance using my multimeter just to make sure that there aren’t any breaks or gaps which there aren’t. Anyway, to mount everything, I’m going to use this base made out of scrap wood that I found.
I drilled an inch and a half hole through it (that’s the same diameter as my secondary coil) and I did that using this saw-tooth drill bit which I was lucky enough to find in one of the toolboxes. I count myself lucky every time I find something in one of our toolboxes.
It’s not as snug as I had hoped for; a little glue should be able to fix that up later. The primary coil sits around the secondary coil and I’m just about ready to begin soldering. I think I’ll use these angle brackets I found solder things together.
I run the resistor between them and and solder wires to either one respectively. Lastly, once I’m done with that, I’ll screw on the switch to the edge which cut the ground wire so that I can turn the circuit on and off by cutting its connection to ground.
Now I think It’s time to begin soldering! The first time I tried powering it us, I had high hopes that I would work, but it didn’t. Here we go… Hmm… it should be on. It has to do with the direction of the primary and the secondary coils.
They each need to have the same direction if you want the slayer exciter circuit to work properly. I’m ready to test my hypothesis, concerning the direction of the windings on the primary coil. I’ve done a little bit of rewiring.
Now the gradient of the windings in the primary must be the same as those in the secondary. That is to say: the coil is rising as it goes around counterclockwise. I’ll start by putting my transistor into the transistor slot that I have made.
.. Now we see if the slayer exciter “excites” … and “slays?” “Excite” it does. Now that the coil is done, I shall turn it on… The first thing I see is the stream of electrons coming off the end of the secondary coil.
(weird sounds) It is particularly dangerous to… (weird sounds again) I’ve noticed an anomalous consequence of running my slayer exciter in my workspace… which is also a laundry room. I think I’ll be able to quickly demonstrate by turning on the slayer exciter.
.. (annoying jingle) As now, our dryer is on the fritz. (jingle continues) …and completely unresponsive to all forms of button pushing. … except that? Where the heck is the “shut up” button on this thing? I want to see how much energy this stream of electrons puts out.
I have this standard paper towel… (annoying jingle) As you can see, it started it on fire… This was a bad idea! (frantic blowing) This jet of electrons should be providing a very small force. I think I will be able to demonstrate with my lighter if I hold it near the jet of electrons.
.. t The flame is being warped by the jet of electrons itself. The field being created by the coil can excite the gasses inside fluorescent lamp. The secondary coil is expending energy make this glow and I can cut that off by moving my hand in between the coil and the light.
This is just a simple incandescent bulb that is filled with argon, xenon, and other (noble) gasses. If I hold it up to the secondary coil, it excites those gasses as well. I’m seeing a purple-orange aurora being created.
Here’s something I don’t get: TIP31C transistors are supposed to be rated for 100 volts at up to 6 amps. Yet, when the voltage is, say: over 15… All of the sudden they do that. Why is that I wonder? I suppose it “possible” that every single one of these transistors in my very large pile of now-dead transistors has simply been a factory dud.
Although I think its something that has to do with my design more than it is that. I suspect it *may* the high voltage from the secondary coil, but I can’t be sure. So I think I’ve engineered a solution.
This wire is an extension wire for what I already have except the wire that goes to the base of the transistor, I’ve soldered in a hundred ohm resistor. Let us see if this prevents the transistors from dying at such low voltages.
Let’s start it low. I don’t want it to be a repeat of my first, failed attempt. (frantic blowing) (smoke alarm sounds) … around 10 volts. It is about the same at it was, now let’s go higher! past 15.
.. … promising… Crap! There is a lot less that I can do to prevent the transistors from heating up. That’s because of the circuit design. It doesn’t output a nice sinusoidal wave, rather it outputs what is closer to a square wave.
The secondary coil is only active while the current is changing through the primary coil, which means that while the current is plateaued, that is just straight direct current going through the transistor, causing it to heat up.
I could try to prevent that by using something that can handle more current like a MOSFET, and I’ve also seen some designs that use multiple transistors to try and keep the current changing, although I’m not going to get into that with this.
I’m now finished with my design, the last thing I did was use electrical tape to hold a 9 volt battery onto the side. Each terminal has alligator clips which can go into the design; that keeps it open to be supplied with any other source of power.
All that need be done now is flip the switch and the slayer exciter is active, albeit not ver powerful only being powered by a 9 volt battery. I’ve got to say, despite its small size, the slayer exciter certainly delivers.
This tesla coil is only the warm-up band. The *real* tesla coil is yet to come… I certainly hope you found this video informative and entertaining. If you can like the video. If you didn’t you can..
. do nothing. I’m Dayton Aardema; until next time.