I know that similar questions have been asked here, but none of the answers seem to work for me. Also, I am new to this site, and I am not much of an expert when it comes to electronics, so feel free to tell me if I forgot any important information, or if you need more information and want me to probe at a specific point in the circuit.

I built a Slayer exciter circuit, using the schematic Electroboom used a few years back. Even though I checked my connections a hundred times, I still can't get it to work.

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I used a transistor of the type BC637, a diode rated for 1 A, and a self-made inductor.

I used an iron nail as the core and wound around 500 windings around it.

Its inductance is 26.8 mH.

My primary is a piece of thick wire with 6 turns.

I made the following observations:

Nothing oscillates. Wherever I probe, I see no oscillation.

At the base of the transistor, I measure around 0.7 V, more or less, depending on the resistor.

If I disconnect the secondary, probe around it, and quickly close the connection between the base and the resistor, I do see a spike down to around -1.2 V, but if I connect the secondary and do the same thing again, the voltage just goes up to the value of 0.7 V because of the resistor being connected to +.

Any help of what I could do to make this thing work and light up my fluorescent lamp would be greatly appreciated.


It works! I made a new coil with a ferrite core, made around 400-500 windings. The primary is now 4 windings. The resistor is 10kO, and everything works perfectly fine, a CFL close to the end of the secondary lights up.

  • \$\begingroup\$ I forgot one thing: The spike downwards just appears, if the base-resistor is 10kO or less. \$\endgroup\$ Dec 4, 2021 at 11:24

1 Answer 1


Iron nail shorts your transformer by having substantial eddy currents. Iron nail can be a good core for DC electric magnet but transformer cores cannot be made of solid conductive material. Try it with no core. Entertainment sites are not anything that should be believed. I guess you have believed one.

ADD due a comment: A ferrite core which is intended to be used in inductors or transformers in the operating frequency works. Ferrites are insulators, so there's no eddy currents. They work as coil inductance boosters due high magnetic permeability. A transformer with a core made of right ferrite material can have superior performance when compared to a coreless transformer.

There exists hundreds of different ferrite materials. Many of the are useless in transformers and inductors. Some of them are designed to attenuate unwanted radio frequency noise emissions by causing losses via complex molecular resonances. You may see them as blocks around power supply- and computer device interconnection cables, for example. Others (as useless for inductors and transformers) are designed to distort the propagation of microwaves in a well controlled way in GHz range components.

  • \$\begingroup\$ Actually, the iron nail was my idea, electrobooms inductor had a ferrit core. Is ferrit non conductive and as such better for this? \$\endgroup\$ Dec 4, 2021 at 11:27
  • \$\begingroup\$ Thank you for your quick answer. I am going to try this with a new inductor. \$\endgroup\$ Dec 4, 2021 at 11:31
  • \$\begingroup\$ It worked!! Thanks again! \$\endgroup\$ Dec 4, 2021 at 13:55

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