Re: [TCML] TC vs "Plasma Speaker" ?

[jhowson4@xxxxxxxxxxx]

Alex, 
I have heard of these little kits before, my understanding is that most of them are so under powered that they require a sharp breakout point to get anything, did you try adding a toroid and a breakout point? 
But not knowing what kit you have exactly. it might just be the case that upon your adding the toroid you change the secondary resonant frequency thus preventing any sparks anyway, as you have already figured out. 


I don't know much about the solid state coils, do they self tune themselves? Maybe someone else on list can answer that one for me. 

You might want to add a larger heatsink to your Mosfet. If you tell me what size you have I may be able to dig one up for you that would be larger, just pay postage. 



Thanks, 
John "Jay" Howson IV 


"Why thank you, I will be happy to take those electrons off you hands." 

----- Original Message -----
From: "b alex pettit jr" <a_pettit_jr@xxxxxxxxx> 
To: tesla@xxxxxxxxxx 
Sent: Sunday, November 6, 2011 7:36:20 AM 
Subject: [TCML] TC vs "Plasma Speaker" ? 

Hello All, 

I recently purchased a 'plasma speaker' kit from Ebay. It works okay, 
but I was hoping I could top load it with a small toroid and get 
longer sparks - not so. 

The intent was to build a 'safe' Tesla Coil for classroom demonstrations 
of electrical resonance to compare to mechanical resonance for my 
mechanical engineering students - the sound input not of real value for this 
purpose. 

The class E amp has few parts : a 4046 PLL drives a complementary transistor 
pair to a single irfp450 MOSFET. The sparks are at best 3/4" long from a banana jack 
( intended to hold the Toroid ). Anything else added to the discharge electrode 
pretty much kills the sparks. The coil gets warm, but does not seem to radiate 
much energy in the form of a visible discharge. 

I built a power supply with selectable output voltages .The unit draws 
44W at 22vdc, 
84W at 35vdc, and ( although no visible change in spark size ), 
183W at 43vdc.... the MOSFET gets hot quickly on this setting ! 

The coil is 2" dia, 7.5" long, #32 AWG - intended to resonate at 1 MHz - this was verified 
by JavaTC. Calculations show the top loading via the 4" x 1" toroid detunes the 
system to 800 KHz. 

Any suggestions as what to change or adjust to allow long sparks ( any sparks ! ) 
from the toriod would be Most Welcomed ! 

Thanks, 
Alex 
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