Single Mosfet Solid State Tesla Coil ( SSTC ) effect of input waveform on streamer shape & profile

In this video I show you the impact of input waveform on the streamer shape and phase pattern of discharges in a single Mosfet solid state Tesla coil SSCT. 4 different input power supply is tested. 1- full bridge rectifier with 220 microF output capacitance, full bridge rectifier with 2420 mircoF output capacitance, single diode rectification with no output capacitor, adjustable voltage regulator in series with single diode with no output capacitor.
It is shown that using adjustable voltage regulator and single diode, give the best output and in most cases the mosfet is on only between 10-30% duty ratio. this helps the mosfet don't hit to thermal breakdown quickly.
input voltage above 110 Volts can lead to mosfet breakdown due high switching losses and overheating. In the future I will show you how to change the circuity so that switching losses is minimized and longer arcs can be achieved. Also a very simple interrupt circuit will be proposed so that individual long arcs is obtained.
Example where to buy adjustable voltage regulator (search in Aliexpress as well you may find them even cheaper)
www.ebay.com/itm/322922899870...
The channel is monetized since 19 January, we are going to get rich :)
The video is made specifically for one of my viewer who is always kind to write a comment after I upload any video, he seems to be interested in Tesla coils, so hopefully this information is useful for him.
Finance: N=38
subs=1086
Available budget (N): 1086-100-38*(38+1)=-496
Storage limit: 2^ln(1086)=127,13

[@RAVI171175]

Very nice & very well explained. I always appreciate when full details are given like that, it's a worth watching video. Just keep it up.

[@HVE]

Thank you

[@jamesparker1839]

I made this exact circuit at home. Just got it going yesterday. I'm having an issue though- for whatever reason I can't seem to get it above 40 volts . If I try it just dies. I have an adjustable voltage regulator on the way from AliExpress after watching this. The differences with mine are: 4 turns on the primary, 980 turns (32awg) on secondary. Also, mine is rectified by two 6A10 diodes in series. I'd really like to know why I can't get it past 40 volts. I wish I could post a couple of pics here. (P.S. I don't own an oscilloscope, I'm fairly new to electronics, but it's extremely high on my list). I am thoroughly and utterly impressed with you. Any advice or help you could offer would be appreciated. Thanks for great content

[@Ngnkg]

If the circuit successful with you tell us

[@nuringtech7153]

can the mosfet be replaced with a 20n60?

[@Jonodrew1286]

Excellent work & explanation of operation - I am curious why some circuits call for a ground on the neutral - as a lot of electrical systems use earth leakage trip or ground interrupt protection which makes it trip instantly 🤔

[@HVE]

If you connect the neutral to ground, the capacitance of the top load to ground can be slightly higher (larger surface area of one electrode), specially if the coil has large height. Also if your low side electrode has sharp edges (when you do not earth it, the sharp edges become even more important), discharges can also form in the lower side. basically there is no preference for discharge to go from the top of the Tesla coil or the lower side if that is floating. Normally because we have the primary winding on the low side we already change the voltage distribution on that side and hence mostly discharges go form the top side. if you ground the lower side, you ensure that discharges will go form the top side.

[@HVE]

@@AdilAdil-qk9ee Hi, i mentioned it in the video, depending on your circuit and switch used, i managed to go as high as 170 Volts.

[@spiderspider1384]

Can i use an irfp460 mosfet for this circuit?

[@HVE]

Yes, certain Mosfets or IGBTs can work, however the voltage at which they break varies. some of them even though are made for 1.2 kV, can break at low input voltage due to resonance between their internal capacitance and the stray inductance of the circuit. so give it a try, but do not expect to go rally high input voltage above 150 V rms of the variac is more or less the danger zone for most of the available switches.

[@canon5068]

This may be a late comment but i was wondering, how did you set the voltage regulator so that it can control the output? Mine pops at 110 volts and doesn't work at 50 volts until the pot is all the way through

[@jamesparker1839]

I have one on the way for mine right now. Which one do you have?

[@ianfisher6561]

Thank you very much for another very well explained and presented video. I know that there are ~750 turns of wire on the secondary coil, but what is the diameter of the former that you have used? Many thanks.

[@HVE]

Thank you, the former diameter is 71 mm. Remember to put something between the primary and secondary coil so that it stays in the center and primary coil does not touch the secondary by accident. use packaging tapes and wrap the secondary coil with a few turns of packaging tape. The tape can melt easily if stroked by an arc. Do not bring close a screw driver or anything near the secondary coil body, if you do so a high frequency arc will form and melt the packaging tape.

[@ianfisher6561]

@@HVE Thank you for your very comprehensive reply. I neglected to mention in my earlier comment that I did not realise that the input power supply would have such an impact on the output. I do know that voltage and current has an effect obviously.

[@Pierre-Marie-9-6-5]

Thank you a lot for your presentation. It is a great experiment. Would you please give us more details about the diodes you use (do you have some references , I mean the TVS 15V diode and the one which is just after thre voltage regulator). Which kind of mosfet can be used instead of the W20NM60 (difficult to find it actually). Thank you in advance for your reply. Have a good day

[@HVE]

Diode after regulator is just a normal rectifier diode which has 20 Amps rating. the TVS is also a 15 volts TVS, 1.5KE15A. Any Mosfet or IGBT will work if you apply lower voltage, but to obtain larger lengths of discharge, only some of them can work. If you can design proper snubber circuitry, maybe most of them will work. In my another video i used an IGBT instead of that mosfet, kzbin.info/www/bejne/eqGwZZt9rrSlo5Y&lc=Ugy4FE2xPIADjLeaqax4AaABAg

[@Pierre-Marie-9-6-5]

@@HVE Many Thanks for your answer and for your link. I will try and let you know my trials results. Have a great day

[@Pierre-Marie-9-6-5]

​@@HVE Thank you, a lot, for your answer. I think your process is very interesting to induce electrical arcs. Using AC currents make it easy (that using high voltage DC current). Thank you again for sharing.

[@ravikumarkaparapu4114]

I didn't understand why there is a discharge spike at the end while switching off. Is it because of the stored energy in the stary inductances and sudden switching off? Interesting video.

[@HVE]

I see that these days you think day and night about stray inductances 🤣. I am not sure what is the exact cause. If i add another 10 microF capacitor in parallel to 0.33 microF capacitor, the spikes are much smaller upon switch off, which suggest an over voltage on the primary side is prevented/damped by larger input capacitance. this means upon sudden switch off maybe there is an over voltage on the primary coil which also results in large streamer on the secondary. But the primary has only a few microH of inductance and should not produce much of an over voltage (the energy stored in that is tiny, while the last streamers are still fat and powerfull). This needs more investigation. Whenever you find the way to get rid of those spikes in your H-bridge, i will also find the answer for this.

[@ravikumarkaparapu4114]

Professor I already found a solution😂. Give me sic MOSFETs and the spikes will go automatically.😂. Thank you for this interesting reply.

[@HVE]

@@ravikumarkaparapu4114 😂, we will buy SIC Mosfet and will use them, but there must be something else which we don't know, and it worth understanding.

[@shawncalderon4950]

Why no schematic?

[@omniyambot9876]

is the secondary grounded?

[@jamesparker1839]

Yes

[@sFeral]

12:24 Dimmer gives the falling edge, so you still have to try the rising edge

[@HVE]

Yes, that will come later

[@For_the-love_of_physics]

wow

[@HVE]

The video is built with you in mind, read the description near the end.

[@For_the-love_of_physics]

@@HVE ok.... Thanks (＾∇＾)ﾉ♪(＾∇＾)ﾉ♪