High Frequency Solid State Tesla Coil (HF SSTC)
By Radu Motisan Posted on December 7th, 2009
Using a single mosfet (IRFP 460) in an Armstrong oscillator, I was able to obtain my first SSTC "light" and the Breakthrough.
The first tests seemed promising, however the breakout needed to be instantiated manually using a screwdriver:
The video shows the very first tests, without any tweaking. The primary was set at 4 turns. The mosfet was getting hot quite quickly, with 100V input voltage.
After a few tests, a value of 6 turns for the primary was selected, and a small top load was added. This greatly improved performance.
The tesla transformer, consists of a PVC pipe 1.5cm diameter, with the 1000 turns secondary, inserted inside a larger PVC tube, with the primary and the feedback coils at the bottom. A very compact design that also allows the two tubes to slide, so the primary+feedback goes closer or further from the secondary, allowing to tune the resonance in a very convenient way. Also the mosfet was much cooler now.
So I've packed everything together in a nice compact setup. Here are a few more pictures and videos with the final setup:
1) Using the HFSSTC at 50V and then at 100V:
2) A few pictures with the HFSSTC:
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3) A last video with the HFSSTC with lights turned off:
A few things I've learned:
1) The IRFP460 works best. And it must be a quality manufacturer, else it might not work (I've tested two mosfets with different manufacturer, and the results were not the same)
2) When winding the tesla transformer, keep in mind that sliding the primary over the secondary helps reaching resonance / better performance / cooler mosfet
3) No breakpoint = dead mosfet - be careful!
4) The device produces strong RF interference, so be careful with all the electronics arround, including the digital camera, your computer, etc . Be careful not to touch any metallic object near the HFSSTC, it will burn you.
5) A topload might help, but better run some tests to see how it goes in your case
6) You will need at least 50V to power this oscillator.
Hope this proves useful,
Radu
Resources:
- my HFSSTC coil on 4HV
By Radu Motisan
December 7th, 2009 | Tags: hfsstc, High Voltage, plasma, tesla coil | Category: Hardware, High Voltage
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December 12th, 2009 at 2:05 am
This is an absolutely BRILLIANT coil. The simplicity of it is just amazing. I just have one question though. How were you able to get the 50-100 volts required for the circuit and what is the minimum amperage needed?
Thanks
Amindha
December 12th, 2009 at 7:52 pm
Thank you! I didn’t measure the current it uses yet, but will do that soon.
Regarding the 50-100V, I have a power source with a toroidal transorfmer 220V->24V@10Amps max. Instead of the rectifier I’ve used a voltage tripler like this:
http://www.coolcircuit.com/circuit/voltage/vt.GIF
December 22nd, 2009 at 6:36 am
Hi
Thank You so much for the reply. I was able to obtain a dula out put transformer that is able to give me 50volts @2amps and 100v@1amp. I was wondering about the secondary coil. 1.5cm diameter for a secondary seems VERY small. Is this a typo or is it supposed to be this. If so, would i be able to incorporate a larger secondary, for example, a 2-3cm diameter secondary. Would this have a negative affect on the coils’ output?
Thanks
Amindha
December 22nd, 2009 at 11:27 am
Hi Amindha,
My secondary coil was built on a 1.5cm diameter PVC pipe, so no typo here
I know it’s small, but my goal was to achieve a high frequency coil, so this fits perfectly.
You can try bigger diameters if you have them already built, but if not, I recommend you try something similar to my design, to be sure it works. To good thing is you need very little wire for such a small diameter.
All the bests,
Radu
March 15th, 2010 at 2:36 pm
That is a great, thanks a lot to post this.