Tabletop Tesla Coil
ฝัง
- เผยแพร่เมื่อ 18 มิ.ย. 2024
- In this video I'll show how i built a battery powered solid state tesla coil that fits on a desk or a coffee table. The coil uses a "slayer
exciter" circuit with an RC snubber and reverse protection diode to avoid damaging spikes of voltage/current during "hard switching". In
addition, 3 FETs are used in parallel to spread out the heat load, which makes the circuit far more reliable.
In addition to those changes, I've buffered the MOSFET gate drive with a push-pull pair consisting of an NPN and PNP transistor. This allows the
gate to be turned on and off much faster, and allows more control over the gate voltage by using a resistor divider on the base of the
transistor(s).
The circuit is interrupted with a 555 timer. It runs at approximately 60 hz and 30% duty cycle. This gives the arcs a more sharp/jagged shape,
but also reduces the power consumption and heat load.
Another useful feature in this driver is the low voltage cutoff circuit, which shuts off the gate drive transistors if the supply voltage falls
below 22V. This ensures that the lithium battery won't be over-discharged.
The maximum arc length i've observed on this coil is approximately 4" (10 cm),
which is very impressive considering that the supply voltage is only 24V.
You may have also noticed that I used a sharp electrode for a breakout but no toroidal / spherical top load. This is to reduce
A few specs:
Primary Turns: 2
Secondary Turns: ~1200
Secondary Diameter: 3.5"
Secondary Height: 6.0"
Input Voltage: 24V (Nominal)
Current Consumption: ~4A
Operating Frequency: ~300 kHz
Interrupter Frequency: ~60 Hz
Duty Cycle: 30%
Snubber R/C: 2 Ohm / 54 nF
Parts I used:
IRF640 (3 in parallel for driving the primary)
2N3904 / 2N3906 (gate drive transistors)
2N3904 for undervoltage cutoff / interrupter pull down
MUR120G (Rail diodes)
NE555 (Interrupter)
LM833 (Undervoltage cutoff comparator)
Music Used:
Kevin MacLeod - George Street Shuffle
Kevin MacLeod - Lobby Time
Serge Pavkin - Crystals
I really like the type of videos you make. idk they just feel right. no bullshit no calls to action no hyped up voice, just you and your project like old youtube
And slayer exciter
One of the best explanations for the design and iteration process! And a pretty clean build too.
Nice as always! Loved the development of the circuit and the Slayer Circuit animation.
Very inspiring- If I still had all my workshop machinery, I would have a go at this. The demonstration was as good as it gets and well done for the additional safety warnings about the dangers of the high frequency affecting the surrounding metalwork.
Nice coil! I made the same "insulated switch" discovery when I built my 833C VTTC. Whenever I would touch one of the toggle switches I would get shocked! I also thought initially that I had a bad grounding system but it was current being induced into my body by the electromagnetic field.
Great video. Highly appreciate it & love what you did. Where simplicity is, you are there. Keep it up.
Fantastic project for the HV enthusiasts! Thanks for sharing.
Excellent vid. Nicely crafted! Just starting out here, built a VTTC with 2 572B triodes. Works well, I think I'm hooked. But your small portable unit is remarkable. Also you present yourself clearly and intelligently, Thank you! Old and retired here, can't deal with too much theatrics and weirdness.
Love your videos. I remember having a plasma globe when I was 10 and quickly learned a penny could be balanced on top and cause very similar shocks/burns depicted in your video! Not to the same intensity but nearly identical burns
Thanks for the tutorial and great explanation in the details!
This will be my next hobby project! :)
I think this video revived my dream of small tesla coil build!! I didnt think such simple driver could work with just 12 volt input.
I have exactly same problem as on video start - bad coil feedback -> lame arcs.
So built up this circuit and it works flawlessly good Job! getting about 2.5 inch off the breakout at 24v nothing getting warm other than the snubber resistor which is doing its job!, time to make he voltage cutoff im debating to use a lm358 instead as this is all ive got in my parts bin, cant wait to get it in a box and portable, thanks for showing how its done ;-)
Hello, by any chance can I contact you by email for assistance? I'm also trying to do the same...
This perfectly shows why I stopped my last circuit design. I did design simple circuits many years ago, really trivial stuff, but even there you start with an simple idea, and then fix the issues ... and simple becomes complex fast. Since I lack experience I can not judge if my finished solution is actually ok or an abomination that still works somehow. So just decided to delegate that when I actually need a circuit. For what I do, i.e. abstract systems design, I just need to know that technical solutions exist.
Love your projects!
So cool! Nicely done
Same here , you can also use relay for particular low voltage cutoff levels .
Reign in Blood!!! Man i had trouble learning that riff as a kid. Sweet video.
I will try your cicuit man thank you so much i've already burned a lot of transistor trying to make a descent slayer exiter ;)
Awesome stuff man
I like that slayer mosfet exciter with BJT's
I love your channel so goddamn much
Great work
Thanks for sharing
Love this sort of info!
Thanks for the video!
I also built a tesla coil, but an sgtc. My supply was a fly back transformer and that driven by a CFL bulb . I got 1 inch arcs max. I really enjoy it. (I don't know English well).
Your english is pretty damn good
(Edit: you earned a subscriber!)
I love this video. It is so honest and informative, i'll use this video as a guide to make a top-notch tutorials in my own future videos. Thank you for sharing your amazing information style and presentation skills.
Did you ever keep working on or come up with some kind of kit or tutorial plan for that super tiny TC you had? The one in the video where you're making a wire wound topload.
Videos like this make me nervous, but not for the reason one may think. I've killed more than a handful of devices (bench PSUs, function generators, etc.) from running/testing my tesla coils next to them. So seeing you run it next to your nice scope is frightening. I don't know if my problem is cheap electronics that I had or what... :(
Great build and video as always!
i saw his monitor flicker in the background when he turned it on, i wonder if its fried
@@Minty1337my moniter flickers alot when i work with high voltage. it goes black if its on if its off it says no signal out of nowhere exc. But it doesnt break
I know what you mean. I was testing a low power emp generator once (maximum range for disrupting unshielded devices around 5m). It managed to kill 2 laptops; they died shortly after the testing. First time I thought it was a coincidence, so ended up with two destroyed laptops.
@@threeMetreJim Unfortunately this is the reason I stopped experimenting with Tesla coils. I have very little free space that would get me away from my/others' electronics.
I built an awesome SSTC that ran off mains a few years ago, but after switching it on once or twice I realized I couldn't do that again :(
Die Wirkung auf in der Nähe stehende elektronische Geräte ist in der Regel tödlich. Wie machen das die Leute nur bei einer 2,5 Mefer hohen Teslaspule? Soviel Platz habe ich nicht hinter dem Haus, und die Regressforderungen der umliegenden Nachbarn werden auch nicht ohne sein. 😜😜😜
You are great at explaining things!! Maybe try a dedicated mosfet gate drive IC to get losses down?
What a creative name
Excellent
Sharing is beautiful,,,,thank you😀
That jar was the star of that show. Surprising that only an empty vacuum tube can do that
Awesome
Pretty epic
awesome!
5:30 you got drains and gates interconnected on your diagram :)
I find various sized metal spoons to be ideal for smoothing out metal tape.
Great work! Just for the record, what level of vacuum are you giving to the home-made plasma jar? Thanks for your so educative video 😊
Gracia Sr. Pirate
Nevermind. THIS will be a fun build
Very beautiful my dear friend
Nice! Wondered if you ever fiddled with electrostatic hold down plate, like those found on old flatbed plotters? I‘m pretty sure you would come up with a DIY solution
Master Nikola Tesla is proud about you, you are good teacher.....yes you have...👍🦁🇲🇽😀
Your circuit is awesome but I have a doubt....are the gate pins of the fets are connected to the drain? It is their in your schematic
I gave myself a burn like that with a MIG welder one day,. I was tacking something, and instead of grabbing a tool, just held it in place. I've done it thousands of times before, but this time, evcerything was just right for the welding current to try and ground through the end of my finger. Hurt like hell at the time, but was worse three days after, and looked just like yours. Could the case be plastic to hrevent accidental burns, or is it being metal a required part of the device?
The larger top load should improve performance, so strange that it reduced it in your case. It's possible that the additional circuit elements like the snubber circuit are just no longer well tuned to the new frequency caused by the larger capacitance.
What's the maximum voltage this circuit can handle? You know I need longer arcs.....and it was tremendously impressive dude...keep it up
people are always telling me "You MUST put transistors in Darlington Config when using multiple in parallel" and I'm wondering why I see people that seem to know their stuff just putting them in normal parallel and don't seem to have any issues... Are there certain circumstances when its ideal and times when not an issue or times when u must or abs can NOT... nice video and great circuit, presentation, appearance very cool and interesting watch!
Darlington connection has nothing to do directly with paralleling transistors, it only may help to provide BJT base current. And this way it's not useful at all with MOSFETs in place of BJTs (see that NPN-PNP pair gate driver in the video).
Do you think your circuit could work well at higher input voltages? Say 40 or 50 volts?
Could you do a variation of the driver using exposed vacuum tubes I know it will be less efficient but I'm going for looks over efficiency I want to build a steam punk style one
Can't go wrong with a battery SSTC!
I could theoretically use a different 555 interrupter right??
Can you share stl file for this project and for the coil winder?
I'm really interested in the continuous operation! What supply voltages can it keep up with?
See I need a high voltage, high frequency source for some... vacuum fun. Particle physics stuff, need to get these millennial particles excited!
An amazing device & great workmanship. A few comments/questions: Use a pvc and/or plastic chassis instead of metal? Immerse any circuit boards in transformer or mineral oil for cooling & the prevention of arcing. Make the primary/secondary coils "plug-in type" so that you can experiment with different lengths & diameters. Can the primary/secondary coils be immersed in oil with just the screw tip exposed?
I use a metal case to serve as a ground plane for the circuit and shield the electronics inside from the huge amount of electrical noise caused by the coil.
The oil thing would definitely work, just more hassle and potential to make a big mess, so usually i avoid it
@@HyperspacePirate how does changing the overall surface area of the ground alter the output?
@@HyperspacePirate Mineral oil gets on everything regardless of how you try to contain it.
@@HyperspacePirate what diameter had your wire?
KSP VAB music is fucking perfect for this.
(I know it's not exactly the same, but it's close)
nice but what type of battery is he using ?
Interesting video 👍
Ok, bye!
I have w doubt you can touch the Spark even when the voltage is that High is because the current is low enough right?....but when touching it you just reached out to it or have to ware rubber shoes and all
great work!
but the circuit at 5:30 seems wrong?
and what is the maximum input voltage this driver can handle?
The max he used was 30 volts, so I wouldn’t go much higher than that
can it be modified to be a musical tesla coil?
Next thing to do is make a full bridge slayer exciter with no fet drivers. That would be something.
Wow modulating sixty hertz may also likely enable low frequency devices to run
I wish I had your intelligence, you are way too smart for human being.
Your push-pull Transistor on schematic are kind of reverse, is that your schematic correct
Special effects or Proximity EMF ?
i have a question if you don't mind
do the voltage rating of the mur120 diodes have to match exactly with the mosfet?
planning on trying this out with irf460 so can i use mur160?
also can i use 100 watts for the 2 ohm snubber resistor?
They don't have to match exactly, but whichever component has the lower max voltage will be the limiting factor
Hello just checking in on that submarine kayak project. I subscribed so I wouldn't miss it.
Love the outtro: Basically, anything can kill you if you're dealing with high Voltage AC. Also, I added a fan!
10/10
The FETS that you used, are they the IRF640 or the IRF640N? And what is the difference between them, if it is of any significance?
Datasheets bruh
neat
is it possible to have a conversation by a coffee table over this noise? or is the camera making it out to be worse than it is?
You have more coffee table conversation pieces than I have brain cells.
جميل جدا يا صديقي
So Where does one acquire 15,000 volt diodes and better still how much are they?
In the triple parallel FET circuit diagrams... why are gates and drains showing as connected together?
Is there some aspect of FET operation that I've failed to understand?
The points where the parallel gate connections cross over the parallel drains are all showing as connected, so this must have been deliberate as these drawing programs don't create connections without the designer designating such - again as far as I know.
What am I missing please?
That might be a mistake in the schematic
Can you do that? Put three FETs in parallel to act like one big FET ?
does that homemade plasma globe produce some X rays?
I know this is an old video but the mosfet gates seem to be connected to The Drain's at 5:27 in the video?? I am about to build this and have a play ;-)
yeah that's an error in the schematic, sorry
Can you help me make a circuit that controls 50 volts and 20 amps
Does anyone have an updated circuit diagram for this project? The configuration of the FET's and 2n3906 looks wrong. I've wasted FET's and BJT's and diodes.
send me your email if you want, I have a pdf with an updated schematic.
Do you reckon haveing 300,000 turns on a tesla coil is overkill?
Any place to get your 3d files?
But I WANT tons of wires everywhere. Cool vid
cant you build the case out of plastic or wood? will that work?
Uhhhh...yeah
Hello, could you provide the schematic files? I would love to build my own
6:25 FRICKIN' ZVS ARCS!
lol dog is like "tesla coil time again? no wonder your wife left you"
@11:35 Are x-rays created here if there's a vacuum in the bulb?
Yes, but that particular bulb doesn't have vacuum inside. If he used vacuum tube, x rays would be created
😃 can you measure Teslar 21700 internal resistance video have ! 13 mili Omp is it new battery or 18 mili Omp is it new or old battery !
In my opinion, having too much insulation is a good idea with anything that uses high voltages
I would love to safely play with one of these medium strength tesla coils, but as I live in on the 4th floor of a 6 floor apartment building, I am wondering about how much and what type of EM interference noise It would possibly be generating to outside my unit into my neighbours dwellings. I woudn't want to cause much in the way of this, as I don't wish to make them upset with my running it in here.
p.s: I would probably purchase an off the shelf already available one... any recommendations?
They'd be too far away to catch any interference. It really only affects unshielded electronics within a few feet
@@HyperspacePirate Thank you Hyperspace Pirate... ok, so that gives me more confidence to check into getting one... * I'd love to be able to make one like you've shown in other previous videos on a simple scaled down version of what's shown here, (very impressive, btw), but I'll purchase a small one first and start playing... and maybe build one later.
@@HyperspacePirate how much frequency could these switch? I have a 1MHz coil with no toroid, with toroid it goes to 650kHz
@@ElIsraelJijijiji This one is around 300 kHz. A typical MOSFET would probably work ok up to around 1 MHz
@@HyperspacePirate I plan to make a fatter secondary, I'm using 38AWG since it was all I had on hand, my new coil will be like 450kHz
I'm trying to build the circuit, but along the way, I have some questions. If someone could answer a few, it would help me a lot:
--Is the snubber filter resistor 2 ohms or 1 ohm? Because in the last version of the schematic, 1 ohm appears.
--Does the value of the capacitors connected at the beginning have to be exactly 3300 uF? Because I have 3 similar ones but they are 2200 uF, although I don't know if it would work because I'm not very familiar with the purpose of placing those capacitors.
--To find the ideal value for the snubber filter capacitor, is it more appropriate to start testing values above 54 nF or below?
--What awg is the primary winding?
1. Snubber resistor's value isn't critical, but keep in mind that lower value resistors will heat up significantly more. You can't use too high value resistors though, because then snubber wouldn't serve it's purpose. I think he used 2 ohms.
2. No, these capacitors are only to provide higher current when circuit needs it, so I think that 3x 2200uF will work just fine
3. In my opinion it's better to start with higher value capacitor and then gradually going down. You can also calculate it's value(he explained how to do it in his video about ignition coil drivers)
@@Antek1234l thank you :)
I can't get the circuit to work with an irfp260n, is the type of MOSFET the problem? I'm also using a very small coil, so could the resonance frequency be too high for my MOSFET?
Try switching the polarity of the primary and/or adding capacitance from FET gate-source (start with maybe 5 nF and work your way up).
If neither of those approaches work, the frequency might be too high. I've started to get trouble with FET switching times on anything faster than ~500 kHz
@@HyperspacePirate already tried to invert the primary windings, didn't work, I'll try to add the capacitors, is the irfp260n good for this circuit?
@@edoardobonfante753 The coil in this video has IRF640 's with 1.7 nF of gate capacitance each, and the gate drive transistors have to work pretty hard to switch them at ~250 kHz. An IRF260 has 5.2 nF of gate capacitance, and you probably have a resonant freq quite a bit higher than 250 kHz, so your gate drive might not be able to keep up
@@HyperspacePirate oh, combined with the fact that i'm not using the BJTs to power the Gates but only the resistor divider you may have found the problem. When I power it up, the MOSFET opens and stays open, shorting the PSU. Also, I can't measure it, but I expect my resonance frequency to be over the Mhz. Maybe using smaller resistances in the voltage divider to have more current? I have some npn bjt but I Don't have any PNPs to use to swithc the Gates, can I use only an NPN?
@@HyperspacePirate I have some BC547 NPNs on hand, could I use only one NPN to drive the gate instead of an NPN and a PNP?
what can i substitue the mur120g diode with? I can't really find it anywhere.
Doing a search on digikey, seems like BYV26, 1N4935, and STTH102 are some commonly available ones that have basically the same specs as MUR120
@@HyperspacePirate thanks
hi,do you think it will work if i wind the secondary with 32 gauge wire instead of 36?
indeed
it would work
A regular CRT high voltage generator does this same exact thing. We called it the high voltage section.
It operated at 15,734.26 Hz.
It’s a standard high voltage transformer. We never, one time, called them a tesla coil.
High current input on the low impedance side - high voltage output on the high impedance output. 25 inch TV’s had 35Kv on their Anodes.
Now for the haters and defenders.
You mean a flyback? No tesla coil runs at 15khz, they usually run in the megahertz range, if you are talking about the flyback transformer it is a completely different thing with different purposes too.
Is it possible to make variable interrupter say from 20Hz to 400Hz?
Yes that's very easy. You just need a 555 timer
@@HyperspacePirate thanks
Does the base of the tesla coil need to be somehow connected to ground or can it operate without touching the ground at all? Also, I would suggest putting some wet clot or tissue paper over the resistors so they boil the water instead of smoking-if of course it is in the configuration to be able to do so....
If it's connected directly to ground it won't work. It needs to be either connected to the gate of the MOSFET or to a buffer connected to the gate
@@HyperspacePirateThank you. So the stray capacitance between the top load and Earth ground is what allows the coil to function? Given capacitors in AC have practically no effect...
@@Hi-zf4bn Yes. The LC tank on the secondary is formed between the coil and the parasitic capacitance - that goes for any tesla coil
@@HyperspacePirate Because I know that certain tesla coils are made with ground rods that connect the other (non-output) end of the secondary to ground, and was wondering if this requires such...
@@Hi-zf4bn This specific circuit doesn't require that. By being connected to the FET gate, the low side of the coil is always within a few volts of ground, while the high side is tens or hundreds of thousands of volts, so the difference is negligible
When he said “metal casing” I basically said “NOOOOO!!!”. What sort of electronics engineer’s go to high voltage project casing is conductive???