# Slayer Exciter with arcs?

Discussion in 'General Electronics Discussion' started by Andremaia, Feb 5, 2018.

1. ### Andremaia

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Jan 31, 2018
Hello everyone from this forum! I am a student trying to beef up my science's fair project..
This is the circuit I used on my first attempt and it works just fine, however, I'd like to beef it up a notch...

I'm trying to get some electric arcs coming out from the top load...So I made a new secondary coil which has about 800 turns and I am also hoping the change my power supply to something higher(Maybe someone can give me a nice recommendation on which I should buy).
I'm also planning on changing my transistor and adding an heat sink as mine probably won't handle the voltage...

So I'm hoping to get a little bit of help on what I should change to get some arcs.

Thanks for reading this post and as always I have some questions:

a)
I researched a bit and I found out that you can actually play music from the electrical arcs as long as you have the right electrical signals, can someone clarify me on that please?
b) is the output voltage on the secondary directly calculated to the ratio of the turns between the two coils times the initial voltage, or does it have some other factors?

2. ### Hopup

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36
Jul 5, 2015
The more turns there are at secondary coil compared to primary,the higher the voltage generally. You can probably increase the sparks easiest by just increasing the voltage of the whole circuitry. Circuit seems to be similar to Tesla coil circuitry so you should get better spark also by getting the resonance between the coils by right ratio between the coil lengths to reduce wire impedance and therefore get the best possible energy transfer.

3. ### FuZZ1L0G1C

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Mar 25, 2014
The music is frequency modulated, carrier wave modulated, or Pulse-width modulated.
One method used is to simply "chop" the HF signal in sync with the negative peaks of the audio, on the primary.
This is CW modulation.
AM wouldn't really work, as when the primary falls below a certain threshold, the secondary spark would be lost or erratic.
Think a triac for lower powers and MOSFET for big 'uns.

4. ### Andremaia

15
1
Jan 31, 2018
But I thought this circuit is already ressonant? unlike the tesla coil which we have to tweak the frequency between the two coils..

5. ### Andremaia

15
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Jan 31, 2018
how would I integrate said CW modulation into my circuit?

6. ### Hopup

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Jul 5, 2015
Yeah it does have automatic resonance between the coils as long as the parts of the circuit can handle it. You can ofcourse still change the frequency/wavelenght with the coils.

7. ### Andremaia

15
1
Jan 31, 2018
any examples how to change the freq/wave length please?

8. ### Hopup

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36
Jul 5, 2015
Every coil has certain capacitance and inductance. It is usually best to use natural frequency in this kind of system/device.

When calculating the wire lengths in meters, 1/4 wavelength divide 75.2, 1/2 wavelength divide 150.5, whole wavelength divide 304 by the frequency wanted in MHz.

22MHz is the frequency you want, then the wire must be 75.29/22 = 3.42meters of wire.

Output voltage:

Divide then wanted output voltage value by the primary coil turn voltage. When the primary has 50 volts per turn and you want the voltage to be 5000v at output you just divide 5000/50 = 100 and you get amount of turns needed.

You can leave some gap between the turns in secondary to get better efficiency.

9. ### BobK

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Jan 5, 2010
No. The frequency is not determined by the length of wire, it is determined by the inductance and capacitance.

Bob

10. ### Hopup

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Jul 5, 2015
I didn't quite tell it sensible way, what I meant was to match/balance the wire length to the established frequency.

11. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,448
2,809
Jan 21, 2010
Yeah, but a straight piece of wire isn't a coil (but it does have inductance)

12. ### Hopup

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Jul 5, 2015
By the wire length I mean the secondary coil wire length.

Since this Slayer Exciter circuit establishes the resonance by itself, doing this might not be sensible, if you had supply of stable radiofrequency and you would use spark gap LC circuit then it would be certainly possible.

13. ### BobK

7,682
1,686
Jan 5, 2010
You are confusing radiating efficacy with resonance.

Bob

14. ### Hopup

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Jul 5, 2015
Thats just how tesla coils are sometimes designed, well tesla himself did advice doing it. I should have not implied that it would greatly affect the performance of the spark production itself. I was little bit too tired at the time I wrote my first reply it has some misinformation for sure