Author Topic: MidiStick V2.0: Next gen tesla coil interrupter  (Read 12589 times)

Offline TMaxElectronics

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MidiStick V2.0: Next gen tesla coil interrupter
« on: June 07, 2020, 12:17:38 AM »
What's the point? Aren't there already plenty other midi interrupters out there?

Since I have always liked musical tesla coils, but been disappointed in how boring most other interrupters out there sound, I decided to build my own:


As far as I know it is the most advanced Midi Interrupter publically available, as it supports full modulation of EVERY parameter of the signal using the VMS (Versatile Modulation System), configurable with a fully graphic scripting language,
and also supports presets which can be selected with the Midi program change command to make it easy to use for those that just want a cool sounding coil :D

Key features of the MidiStick:
  • Compact: no larger than a usb stick
  • Four voice polyphonic (eight with HyperVoice enabled)
  • supports VMS and comes with a preset that even includes drum emulation
  • DAW compatible! VMS supports midi CCs as parameters, so every sound aspect can also be controlled from the DAW
  • Easy to use: just plug it in, select which coil is connected and play. No midi to serial conversion necessary
  • Open source. All of the code and PCB files are on my github
  • Supports stereo mapping
  • Coil parameters are fully programmable, so it can be used with every coil that has an external interrupter input
  • Supports both HFBR series and If-e96 transmitters
  • Can emulate the famous MOS6581 sound chip from the C64

Where can I get one?
You can buy one from me or make your own :)
I sell them in the shop on my website: https://tmax-electronics.de/product/midistick-v1-2/
All of the pcb files you need to make one yourself are here (hot air soldering station is required): https://github.com/TMaxElectronics/MidiStick_PCB
The firmware is here (you will need a pic32mx compatible programmer to burn the bootloader): https://github.com/TMaxElectronics/MidiStick_Firmware

Here are some demo videos (the VMS demo is unfortunately not on a coil, since I couldn't go to the HV lab for a while due to the lockdown and running it in my basement is a little boring):

Disclaimer: I did edit this post to make it look better, I didn't start off posting this :D
« Last Edit: May 14, 2021, 10:06:27 PM by TMaxElectronics »

Offline Max

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Re: compact midi interrupter
« Reply #1 on: June 07, 2020, 10:36:18 AM »
Hi TmaxElectronics,

Love that minimalistic approach! Would you share some more details? What MIDI commands does it support? How do you set your ontime, etc.

Thanks!
Max

Offline TMaxElectronics

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Re: compact midi interrupter
« Reply #2 on: June 07, 2020, 01:05:56 PM »
Sure!
As i said, the software isn't 100% yet, so some things i still need to implement, so far it supports Midi Volume control (with minimum and maximum on time), Pitch bend and of course note on/off with two voices. It also has attac and decay.
I still plan to add frequency and amplitude adjustable FM & on time modulation, and want to allow it to play midi files with both hands of a keyboard on one track (low and high notes) without requiring modification of the midi file.
That small pin header next to the usb stick will be configurable as either an input or output, so it can be used to test wit a speaker or connect an E-Stop button or something like that.

The thing i am working on at the moment is configurability, because it is not the most user friendly if you need to recompile the code to change the max on time :P
It will be done with a small program, that saves the configuration to the stick, and maybe then use the program change command to switch between saved coils (?). Might be dangerous though if there is a programm change command in the midi file, though i might just lock it once it has started to play music, not sure about that yet. I also still need to decide how the config utility communicates with the thing, if I can convince the USB lib to have a dual role, then it would use a custom HID interface, otherwise i will use another midi channel for that. It would then technically not be midi compatible though and any controller change commands on that channel might mess up settings, so i hope to get the HID thing working.

I also want to make a 3D printed housing for it, but i don't have enough resin to print at the moment.

Offline futurist

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Re: compact midi interrupter
« Reply #3 on: June 07, 2020, 05:11:55 PM »
Nice project, thanks for sharing!

I'd love to try it myself!

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Re: compact midi interrupter
« Reply #4 on: June 07, 2020, 11:02:34 PM »
Oh - two notes. Cool. I'm curious to see your code. Btw. which microcontroller is it?

Configurability/Usability is an important point! The best features are pointless if they are a pain in the ass to use. I opted for a touchscreen for my MIDI interrupter (https://highvoltageforum.net/index.php?topic=1020.0). Although powerful and easy to use its an expensive solution. For your "tiny-Interrupter" I think a program on PC is the only viable solution. Any additional hardware would contradict your "usb-stick" solution.
I also think that you need to be able to change the ontime easily while its running. I already had MIDI files which got unexpectedly intense, so I had to reduce the ontime. MIDI volume is not really an option since it is controlled by the MIDI file (= your settings could be overwritten at any point).

Program changes are in my opinion not the best way to go. They happen quite "frequently", meaning in 10 MIDI files you download there will likely be one or two files which do program changes in the middle of a track. Of course you can remove them, but it is still a risk. Some MIDI programs always send a (default) program at the beginning to make sure the device knows how to play. Since you already mentionned ADSR, you could use program changes to switch between different ADSR timings?

I would suggest to use the SysEx commands. They are there for exactly this purpose: allowing manufactors to implement device specific commands, to configure things that are not covered by the MIDI specs. The command is 0xF0 (for chn. 0) and can be followed by any amount of data bytes.


Kind regards,
Max

Offline TMaxElectronics

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Re: compact midi interrupter
« Reply #5 on: June 07, 2020, 11:55:38 PM »
It's a pic32mx270f256b, very much overkill for what i am doing, but its my go to pic with usb and I usually have some in stock so i used it. I'm using two timers combined in 32bit mode for each note, with the interrupt starting the fifth timer that controls the on time.

Quote
I opted for a touchscreen for my MIDI interrupter
That looks great! I was thinking of something similar, but since I have a laptop around to play the midi files anyway, I decided make it small so I don't have to setup as much stuff and also don't have to worry about power for the thing.

I also got the dual role working, so I can access the device directly, without needing to go through midi (didn't know thats what the SysEx cmds where for though :D ).
As for ADSR timings, the user would be able to add different configurations to each saved coil, which can then be selected through MIDI program change cmds. (So P1 - P2 would be coil one and P3-P6 would be coil two for example)
Kind of like this

And then only allow switching between different coils, when the last command was a controller reset or something else, that would never be sent as part of a song.

Since the software can communicate with the synth independently of current midi commands, changing parameters on the fly should be easy enough, though I will still use the midi volume control, just with an adjustable minimum and maximum on time (i might make that be able to be turned off).



Offline Mads Barnkob

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Re: compact midi interrupter
« Reply #6 on: June 08, 2020, 08:40:28 AM »
Very nice project and certainly is no shame to remove that cheap-usb-to-midi cable that properly is just picking up more noise than doing good!

Would it be possible to slap 8 of these in a USB hub and have 8 instruments or is it showing as 8 voices? I am not very experienced with how MIDI really works.

I am in for 2 of these, if two are needed to play dual coils. Which I assume given there is only one optical output :)
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Offline Max

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Re: compact midi interrupter
« Reply #7 on: June 08, 2020, 11:10:34 AM »
I’m still not a fan of the dual use of the program change commands, especially if there is a second independant access. However adding the check with the controller reset should be fine and prevent unintended changes. I guess it‘s rather a personal preference than an objective advantage/disadvantage.

That microcontroller seems powerful enough to do more than two voices! 4 at least should be possible.

Of course the MIDI volume command should be respected and used! Maybe my last post was misleading. What i meant was that there needs to be an independant possibility to set the limits within which all MIDI commands operate. And that‘s what you want to do if I understand right.
Minimum ontime is an interesting idea. While I understand why one would want to do it, I thought it would be problematic for fade in/out effects and for ADSR. I‘m curious to see how it behaves in reality!
I forgot one thing in my last post: you mentionned „ontime modulation“ what exactly do you mean with that?

@Mads from a MIDI point of view this will work like a charm. The question would rather be how you configure them; does the configuration software properly support multiple ones.

Kind regards,
Max

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Re: compact midi interrupter
« Reply #8 on: June 08, 2020, 02:22:47 PM »
Hi-

nice Work! I would be really interested if you would do a small production run- is one of the 24 boards still available? Would be great if you had the time to send me a PM!
My coil works not too bad so far but my experimets with making it play music were deafening... ::)

Kind regards
Roman

Offline TMaxElectronics

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Re: compact midi interrupter
« Reply #9 on: June 08, 2020, 03:44:31 PM »
Quote
That microcontroller seems powerful enough to do more than two voices! 4 at least should be possible.
It Certainly would be. Right now i am using 100% hardware timing, but the thing is likely fast enough to run a software-postscaler on those timers, maybe even using some DMA magic ;)
For now i will focus on getting the software together though and once thats done add more features!

Quote
I’m still not a fan of the dual use of the program change commands, especially if there is a second independant access.
I'm not so sure about them either  ::)
My thought was that it would allow for limited configuration without needing the software, but i am starting to question wether that is actually a useful feature.

Quote
Minimum ontime is an interesting idea.
I have had issues on my coil (a VERY shitty small one, my big one isn't quite done yet) that at short on times was not able to strike the arc sometimes and it sounded bad when using very long attack or release times, i hope to fix that with that setting.

Quote
you mentionned „ontime modulation“ what exactly do you mean with that?
It will make the controller continuously vary the on time while a note is playing (by a varying amplitude and at varying frequency), creating an arc that sounds like it has more than one note playing, while in reality it doesn't (at least thats what it sounded like last time i experimented with this). I would post a video, but unfortunately I don't have a working coil at the moment and can only test with a speaker  :-[

Quote
Would it be possible to slap 8 of these in a USB hub and have 8 instruments or is it showing as 8 voices?
Honestly i don't know how USB Midi behaves in that situation, i have only ever used one synth at a time ;)
But i would expect it to show up as different midi out devices, instead of one midi out with multiple channels. My software only supports one additional midi out device so a workaround would be needed (which is exactly was i am trying to avoid with this board)
For that it might be a better solution to just make on synth with multiple interrupter outputs, an FPGA for the timing and a uController for USB Comms (for just two outputs the pic alone would be fine though i think). That might be a project for a later time if I ever have more than one Coils simultainiously :P

I would also like to hear your thoughts on an idea:
What if, in addition to having the settings dialog, there was a seperate (always on top) window for live performance, that has a panic button (incase the midi software messes up), the option to override the current ADSR & modulation settings from the selected programm and the selector for the current coil configuration.
Would you guys find that useful or not?

Offline TMaxElectronics

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Re: compact midi interrupter
« Reply #10 on: June 08, 2020, 07:29:01 PM »
quick update: I more or less got the ui layed out the way i envisioned it:

what do you think? The programms are now unrelated to the selected coil, and the live preview of parameters is working, now comes saving&loading

I'm not sure about the top label though (the "Connected to..." one)... it looks kinda stupid  ???

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Re: compact midi interrupter
« Reply #11 on: June 08, 2020, 10:01:47 PM »
A status bar the bottom has been windows standard for many years, add one :)
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Re: compact midi interrupter
« Reply #12 on: June 08, 2020, 11:37:52 PM »
Minimum ontime is an interesting idea. While I understand why one would want to do it, I thought it would be problematic for fade in/out effects and for ADSR. I‘m curious to see how it behaves in reality!

I think that minimum on-time is must-have feature for good midi playback. Bellow some on-time the coil won't output a spark, or it will be too quiet
My min. on-time is set to around 40 us, and less than that the midi playback sounds bad

Offline davekni

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Re: compact midi interrupter
« Reply #13 on: June 09, 2020, 05:56:30 AM »
Yes, I also find minimum on-time helpful.  Besides enforcing a minimum, I'm making pulse width proportional to sqrt(volume).  That subjectively seems to help, but I don't have good comparisons.  At least for pulses towards the short end, current is growing roughly linearly with time, so total energy is growing as time squared.  Sqrt() undoes that square relationship.  For longer pulses, primary current envelope is more complex, especially with the beat between primary and secondary frequencies.  The sqrt() function isn't a match for long pulses.  On my coil it works out well, however, reducing excessively-long pulses.

The sqrt() function is applied after merging or separating pulses that are too close.

I'd love to make a more accurate translation from instantaneous note volume (including any other notes outputting a pulse at the same) to pulse width.  The mapping would need to be quite complex, perhaps too complex and variable to be within reason.  Spark behavior depends heavily on pulse history - how much of an ionized air path is built up.  Relevant history appears to go back much farther than I was guessing.  And, of course, ground strikes make a significant difference too.  My hope was to set up a microphone and measure sound impulse energy vs. pulse width.  The long history makes that impractical.  If only one or two pulses of history matter, could capture that before echos interfere.  Anyone have access to an an-echoic chamber for coil testing? :)
David Knierim

Offline TMaxElectronics

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Re: compact midi interrupter
« Reply #14 on: June 11, 2020, 10:04:45 PM »
Just thought I'd post another update:

I have now got the PC software more or less finished. I still need some way of selecting the active coil configuration and give it the ability to update the software on the synth.
The UI now (kinda) has a status bar on the bottom left below the tree view, but i am not 100% sure if i like it that way...
Changes are also not automatically sent to the device at the moment, because I want to keep NVM writes to a minimum, even if it can handle at least 20.000 writes. At least the program marks any changed settings on orange, as you can see on the left.


The other features work; it can save Coil configurations and Midi programs to the synth and the synth can recall them when the Midi player tells it to (at least the programs). Attac and release also work, sustain and decay don't yet though :/

Offline TMaxElectronics

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Re: compact midi interrupter
« Reply #15 on: June 14, 2020, 04:15:14 PM »
I've just released a beta firmware if anyone want's to have a look:
https://github.com/TMaxElectronics/MidiStick_Firmware

Still some coding to do though, sorry it is taking so long. The project is a little more complex than I had anticipated  ::)
If i'm lucky i will also have my larger coil working to test with soon! :D

Offline TMaxElectronics

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Re: compact midi interrupter
« Reply #16 on: June 19, 2020, 12:48:29 AM »
So i am now working on proper decision making logic to decide which of the notes to play and am not sure in which direction to go.
At the moment I have a list that contains all notes currently on, and wan't to select the most important ones, musically speaking .
My initial plan was to get the set of notes that are part of the melody (right hand) and those that are part of the **** (i actually don't know the name for those  :-[ ) from the left hand, then play either one note from each, only the melody or only the left hand.
But some tracks don't seem to follow the piano scheme but still have multiple notes on... So either I just ignore the tracks that have more than two simultaneous notes, since most songs are available in tesla friendly versions, or to make a better system.
Maybe just checking if the note is higher than the median of currently playing notes, if there are more than two, and then using voice one for the most recent upper one and two for the lower one, but that relies on the piano style system again.

What are your thoughts on this? Is a smart note controller a useless feature or actually useful (by allowing un-edited songs to be played).

Offline Max

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Re: compact midi interrupter
« Reply #17 on: June 19, 2020, 08:11:25 PM »
Hello TmaxElectronics,


I had a quick look at your code when you released it. I wondered about how you solved ADSR. It looked like some amplitudes were hard coded? And i didn't quite understand why A, D, S and R were implemented differently. If you stay with linear curves (e.g. linear rise for A, linear fall for R), you actually don't need 4 different implementations. If you have a look over here at my code it is basically this (assuming we are doing an attack):
Code: [Select]
gradient = (attackAmplitude - releaseAmplitude) / attackDuration;
noteAmplitude += gradient * timeDiff;
if ((gradient >= 0 && noteAmplitude >= attackAmplitude) || (gradient < 0 && noteAmplitude <= attackAmplitude))
{
    noteAmplitude = attackAmplitude; // Prevent overshooting
    // Target reached, proceed to next mode (here: decay).
}
The big advantage is that it does not matter if the gradient is positive or negative. That means your ADSR parameters can be completely arbitrary. Doesn't matter if sustainAmplitude is higher or lower than decayAmplitude.

Quote
So i am now working on proper decision making logic to decide which of the notes to play and am not sure in which direction to go.
At the moment I have a list that contains all notes currently on, and wan't to select the most important ones, musically speaking .
Thought about that, too. The short answer is: there is no "perfect" way to do this. Here is why: Accompaniment (the term you were looking for, if my translator is correct) does not stay in a strict range. Even on a piano (playing it for 14 years now ;) ) it rarely stays in "its own region". Sometimes the melody is in the middle, with additional lower and higher notes. Admitted, this is more problematic if you have many voices, as f.ex. in an unmodified MIDI from the internet or simply the original version of a piece. Once it is reduced to two voices only, it is a lot more often true that the melody is higher than the accompaniment - and still there are exceptions.
Second option would be to select by volume/velocity. This would probably work in quite a few more cases than the previous idea and makes musically more sense. Its the melody you want to have "in front" of all the rest. The problem with this kind of detection is that many MIDI files don't have real nuances (variation in volume) - especially not inside the same track.

So if a musical recognition of the melody is not that easy, what other solutions are possible? Simplest option (although musical nonsense): put all notes in a buffer. If the buffer is full, overwrite the oldest note. Thats what I have done. Considering the high limit of 8 voices for my interrupter the buffer strategy really isn't that important anymore.
In your case however you could try a combination to get the best results. What if you had a buffer for each voice? Except for some very few (and often low quality) MIDIs you never have melody and accompaniment on the same channel. This means that you would effectively have one buffer with all currently playing notes of the melody and one with the active notes of the accompaniment. Then you could - from each buffer - select the one with the highest velocity and only play that one. And in case they are all the same, you simply take the most recent note. Additionally you could say that if the "accompaniment buffer" is empty, you take two notes from the "melody-buffer". Then even the crappier single-channel MIDIs will play with two voices. The advantage of the dual buffer solution is that your accompaniment can‘t overwrite your melody. If there are melody notes, at least one of them will be played.
In your desktop tool you would be able to assign any channels to any of the two buffers. It is very useful to listen to multiple channels since it is quite common that the melody is divided in multiple channels, which don't play at the same time. It is mostly done if the melody switches the instrument.

Hope this makes sense and is useful. :)


Kind regards,
Max
« Last Edit: June 19, 2020, 11:58:20 PM by Max »

Offline TMaxElectronics

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Re: compact midi interrupter
« Reply #18 on: June 20, 2020, 02:39:26 AM »
Quote
I wondered about how you solved ADSR.
I based my implementation on one i did in VHDL for an FM Synth a while back, that's why it has a state machine ;)
I also wanted to use exponential waveforms, since I felt they sounded better than linear ones, especially with long release times from things like guitars.
Basically the way I have implemented it is by using a multiplier (Midi_currOT1Mult/Midi_currOT2Mult) that scales the output on-time. In the different states it multiplies the appropriate coefficient with the multiplier, so you get the formula

Code: [Select]
onTime = maxOnTime * coef^t   ;   with coef > 1 for attac and coef < 1 for decay&release
and then checks if the required on-time is reached:

Code: [Select]
if(Midi_currReqNoteOT1 > 0){   //this checks if the note is still turned on (by the midi controller)
   Midi_currOT1Mult *= Midi_attacCoef; //then it updates the multiplier
   if(Midi_currOT1Mult > 1 || Midi_attacCoef == 1){  //checks if the note has reached the target on time (for attac the multiplier must be 1) or if attac was disabled by setting the coefficient to one
      Midi_currOT1Mult = 1;    //we need to do this if we entered this code because the coefficient is one, so we instantly get to 100% on time
      Midi_currNoteOT1 = Midi_currCoil->minOnTime + Midi_currReqNoteOT1; 
      /*update the on time that the timer interrupt actually uses (technically we still need to multiply Midi_currCoil->minOnTime with Midi_currOT1Mult, but since the coefficient is one we can ignore that)*/
      Midi_adsrState1 = DECAY; //advance the state machine
   }else{  //if we have not reached our target on time, we adjust the current on time with the multiplier value
      Midi_currNoteOT1 = Midi_currCoil->minOnTime + (uint16_t) ((float) Midi_currReqNoteOT1 * Midi_currOT1Mult);  //the requested on time is always what needs to be added to the minimum on time settings of the current coil
   }
}else{
   Midi_adsrState1 = RELEASE;
}
I hope those comments explained the code a bit better.

Quote
It looked like some amplitudes were hard coded?
No that shouldn't be the case ??? My code is a bit confusing though I must admit ::)
All of the Waveform parameters (min/max on time, duty cycle) are adjustable by software and saved in the NVM, and then read from the Midi_currCoil struct.

I'm also wondering which fiber-optic connectors other people are using for their coils, the transmitter I'm using is from a range with ST,SC,FC and SMA versions, but i think some coils use just bare fiber (like the OneTesla one), so those would at least need some kind of an adapter to fit. Maxs Syntherrupter uses SC if I recall the post correctly

Offline Max

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Re: compact midi interrupter
« Reply #19 on: June 20, 2020, 05:33:57 PM »
Ok I see I should have spent more time with your code before commenting it.

It is true, I'm using SC connectors. Not because they are popular, better or cheaper, but because I already had 10m SC cables. I think the most common type in the tesla coil community are ST connectors and "no connector" (those industrial transmitters where you put the raw fiber in).
Edit: For my interrupter its no problem to use an uncommon connector since I don't sell them. It's mostly made from off-the-shelf parts that don't require soldering. Additionally, selling it with a (machined!) metal enclosure and all connectors mounted would make it pretty expensive.
The only thing I could maybe design and sell would be a tiny PCB with a MIDI optocoupler and the optic transmitter including its driver transistor. But that's really just a 5min job... I don't think this would really be interesting for someone who has successfully built a whole tesla coil.

Kind regards,
Max
« Last Edit: June 20, 2020, 05:42:13 PM by Max »

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Re: compact midi interrupter
« Reply #19 on: June 20, 2020, 05:33:57 PM »

 


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September 23, 2021, 05:46:38 PM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 23, 2021, 11:12:25 AM
post Re: Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Netzpfuscher
September 23, 2021, 08:49:51 AM
post Re: Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
September 23, 2021, 06:15:34 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
davekni
September 23, 2021, 05:48:40 AM
post Re: Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Uspring
September 22, 2021, 07:21:12 PM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 22, 2021, 10:41:20 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
davekni
September 22, 2021, 07:07:48 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 22, 2021, 05:26:40 AM
post Re: Measuring TC secondary parameters
[General Chat]
MRMILSTAR
September 22, 2021, 05:14:30 AM
post Measuring TC secondary parameters
[General Chat]
Duane B
September 22, 2021, 05:01:22 AM
post Re: Load resistance and discharge terminal for my 14-stage CW multiplier
[Voltage Multipliers]
MRMILSTAR
September 21, 2021, 10:33:34 PM
post Re: Futurist's DRSSTC 0.5
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
September 21, 2021, 07:21:50 PM
post Re: Load resistance and discharge terminal for my 14-stage CW multiplier
[Voltage Multipliers]
klugesmith
September 21, 2021, 05:24:35 PM
post Re: BrOdin coil - High power Big sparks!
[Dual Resonant Solid State Tesla coils (DRSSTC)]
futurist
September 21, 2021, 04:18:47 PM
post Load resistance and discharge terminal for my 14-stage CW multiplier
[Voltage Multipliers]
MRMILSTAR
September 21, 2021, 06:30:44 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
davekni
September 21, 2021, 06:04:52 AM
post Re: BrOdin coil - High power Big sparks!
[Dual Resonant Solid State Tesla coils (DRSSTC)]
fh89
September 21, 2021, 03:56:28 AM
post Re: Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
johnnyzoo
September 20, 2021, 09:24:10 PM
post Re: BrOdin coil - High power Big sparks!
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Uspring
September 20, 2021, 05:07:43 PM
post Re: Large Rectifier Tube
[General Chat]
Benbmw
September 20, 2021, 04:12:27 PM
post Re: Proper phase lead adjustment at the input
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Chrisader
September 20, 2021, 10:40:33 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 20, 2021, 10:39:59 AM
post Re: BrOdin coil - High power Big sparks!
[Dual Resonant Solid State Tesla coils (DRSSTC)]
futurist
September 20, 2021, 10:38:31 AM
post Re: Large Rectifier Tube
[General Chat]
klugesmith
September 20, 2021, 07:07:55 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 20, 2021, 06:03:57 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
davekni
September 20, 2021, 05:31:57 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 20, 2021, 04:59:17 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 20, 2021, 04:28:03 AM
post Re: Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
September 20, 2021, 12:53:39 AM
post Re: Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
johnnyzoo
September 19, 2021, 11:09:37 PM
post Re: Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
AstRii
September 19, 2021, 09:47:14 PM
post Re: Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
September 19, 2021, 08:28:05 PM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
davekni
September 19, 2021, 08:19:01 PM
post Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
AstRii
September 19, 2021, 07:58:09 PM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 19, 2021, 03:16:40 PM
post Re: Driverless MOSFET SSTC
[Beginners]
AstRii
September 19, 2021, 01:32:47 PM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 19, 2021, 10:15:24 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
Magneticitist
September 19, 2021, 06:32:18 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
davekni
September 19, 2021, 06:06:44 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 19, 2021, 04:14:18 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
Magneticitist
September 18, 2021, 11:33:37 PM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AstRii
September 18, 2021, 10:42:45 PM
post Re: BrOdin coil - High power Big sparks!
[Dual Resonant Solid State Tesla coils (DRSSTC)]
fh89
September 18, 2021, 09:05:03 PM
post Re: BrOdin coil - High power Big sparks!
[Dual Resonant Solid State Tesla coils (DRSSTC)]
fh89
September 18, 2021, 09:00:32 PM
post Re: BrOdin coil - High power Big sparks!
[Dual Resonant Solid State Tesla coils (DRSSTC)]
AstRii
September 18, 2021, 08:34:15 PM

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