Tesla Coil - Slayer Exciter circuit

Thread Starter

HeroKasper

Joined Dec 18, 2019
12
Hi,
I've been trying to build a Tesla Coil for a couple time now, and i decided to build this Slayer Circuit, the only problem is i have no real knowledge of electronics, i'm not exactly sure why it isn't working or how to fix it.
I have blown up two TIP31C transistors by trying to connect the circuit to my 24V Power supply.
I have a limited amount of available voltages to use: 3.3V, 5V, 7V, 8.7V, 12V, 15.3V, 17V, 24V.
Any ideas, suggestion or modifications for my project? I would be very thankful for any help, and sorry for any english errors.
 

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SamR

Joined Mar 19, 2019
2,108
Hard to tell much from your schematic as it does not show the diode. But if you are blowing up a TIP31C it's not from V on a 24VDC power supply but from current. Something is shorted. The picture of the xstr shows legs close to the heatsink. Do you have a multimeter? Check the legs to the heatsink for shorting.
 

Thread Starter

HeroKasper

Joined Dec 18, 2019
12
Hard to tell much from your schematic as it does not show the diode. But if you are blowing up a TIP31C it's not from V on a 24VDC power supply but from current. Something is shorted. The picture of the xstr shows legs close to the heatsink. Do you have a multimeter? Check the legs to the heatsink for shorting.
There is no diode in the circuit, i'm not even sure there was supposed to be one in the first place! If so where should i put it? Also i've just checked and it seems the heatsink and the transistor indeed were shorted, will fix that on the next run, anything else?
 

be80be

Joined Jul 5, 2008
2,042
Like SamR said a led works I used 2 1n4007 I've tried one of them the Led or 2 in4007 worked the best.

But there 2 things that has to be right the diode or led needs to be there and the smaller coil need to be tuned my case 8 turns worked
one i made before it took 6 turns
 
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SamR

Joined Mar 19, 2019
2,108
seems the heatsink and the transistor indeed were shorted,
The metal top of the xstr IS tied to one of the legs. There is usually a silicone mat under the xstr to insulate it from the heatsink or in the past it was a sheet of mica. If your transistor is grounded out you will have trouble unless it is the emitter connected directly to ground which it should be.
 
I'm new at this too. I use this with success and it looks similar to what you're doing
FMQ4KXUIRXSZSBW.LARGE.jpgSource: https://www.instructables.com/id/How-to-Build-a-Slayer-Exciter/

If anyone has any time I'm curious as to why this resonant slayer circuit can generate high voltages at 130khz or whatever it is but when I hook up a signal generator and find some spike in voltage (some resonance) its no where near lighting a light bulb like this circuit? Is there something I'm missing as to not being able to do the same on a signal generator vs this circuit?
 

SamR

Joined Mar 19, 2019
2,108
With a 1:400 turn coil the 9VDC in gives 9X400 ~= 3.6Kvac out. My signal generator ramped up to 20VAC @ 60Hz gives 7VAC rms out. But it is supplied by a 5V wall wart at ?A/W. So there is no real available current. IE no real power. I barely get a tiny blue corona off the end of the coil wire but it does have enough energy to ignite paper and will light up a fluorescent lightbulb. That is with 20-30 VDC input from my bench PSU.
 
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Thread Starter

HeroKasper

Joined Dec 18, 2019
12
I'm new at this too. I use this with success and it looks similar to what you're doing
View attachment 194848Source: https://www.instructables.com/id/How-to-Build-a-Slayer-Exciter/

If anyone has any time I'm curious as to why this resonant slayer circuit can generate high voltages at 130khz or whatever it is but when I hook up a signal generator and find some spike in voltage (some resonance) its no where near lighting a light bulb like this circuit? Is there something I'm missing as to not being able to do the same on a signal generator vs this circuit?
This is great! how about if i wanted to operate on 24V what adaptations should i make?
 
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