Step 2: The Driver Circuit

Picture of The Driver Circuit
This design is very simple and only uses four components! It is also very versatile and the input voltage can be as low as 5 volts or higher than 18 volts if the transistor is attached to a heat sink.


-   5 to 18 volts is fed into the circuit, a resistor (R1) is placed before the Base pin of the transistor in order to limit the amount of current the pin receives. If too much current is allowed into the Base pin the transistor can produce excessive heat and fail.

-   One end of the secondary (L2) is connected to the Base pin of the transistor in order to feed it with oscillations. The two diodes (D1 and D2) prevent the oscillations from going directly to ground. (Learn more about oscillations and why they're important, below).
-   The transistor is made up of three pins: the Collector, the Emitter, and the Base. If you were to think of the transistor as a garden hose spigot (See picture 2), the Collector would be the reservoir of water. The Emitter would be the hose and the Base would be the valve that would allow water from the reservoir (Collector) to the hose (Emitter). The valve (Base) is in the closed position (no water flowing) until it is given a little nudge. When it receives a nudge, the valve opens and a lot of water is allowed to flow from the reservoir through the hose as long as the valve is still getting a nudge. However, as soon as the nudge goes away the valve will close, cutting off the water from the reservoir to the hose until the valve gets another nudge.

-   When the Base receives a little bit of current, it closes the circuit and electricity is allowed to flow through the primary coil (L1). However, electricity likes to take the path of least resistance so when the electricity is allowed to flow from the collector to the emitter (~0 ohm resistance) it will stop flowing to the base because there is 47,000 ohms of resistance there. When the electricity stops flowing to the base, the base will open up the circuit again until the resistor offers less resistance than the Collector-Emitter path. This cycle repeats itself many times a second.

-   The primary coil collapses when the electricity stops flowing through it, when this happens, the secondary coil picks up the magnetic field and converts it back into voltage which gets stepped up to around a thousand volts in the process. The top load acts as a capacitor and increases the output from the secondary causing electrons in the air to become excited.

-   Finally, the oscillations from the secondary coil are fed back into the transistor in order to 'tune' or achieve maximum output from the Slayer Exciter.
akashs2029 days ago

I did everything as told & my transistor, diode &resistor are heating up but my coil wont work. My science fair is in 2 days so i need HELP!! fast.

Chip Fixes (author)  akashs2029 days ago
If everything is warm to the touch but not hot then that's a good indication that the driver circuit is working properly. Try flipping the ends of the primary coil around and if that doesn't work, try changing the top load.
PlasmaGuy1013 months ago

If your theory was correct, than the circuit would still oscillate if the primary was replaced with a light bulb. infact, the bottom of the secondary provides negative feedback, and this is what switches off the transistor.

wizard7222 years ago
About how much current does this use?
Chip Fixes (author)  wizard7222 years ago
It depends on the input voltage but it should be around 100mA at 12v.
tesla man3 years ago
Hi! Its me again! The slayer exciter does use an oscillator, right?
tesla man3 years ago
Hi! Its me again! The slayer exciter does use an oscillator, right?
tesla man3 years ago
Hi! Its me again! The slayer exciter does use an oscillator, right?