My 160 (?)mm sstc

[oneKone]

Did you build it yourself or from a oneTesla kit? I don't notice any pops or anything like that, but then again I've never been listening for one.

Does it look like a kit? lol

Friend of mine bodged battery, some LEDs, switches and arduino nano in battery pack case
Today I tried figuring out what is wrong with it, and it turns out it's much worse than I thought, check out for example:


It's just one note playing, yellow signal is note-on midi message, and resulting pulses should all be evenly spaced. This happens to almost every note

How are you playing the midi file?  And what version of the Arduino ide did you use?

[Mads Barnkob]

uzzors2k published a MIDI modulator back in 2013 ( http://uzzors2k.4hv.org/index.php?page=midiinterrupter ), there is a good chance that oneTesla used all kinds of public available code for their own.

I just happened to stumble upon his site and saw that a error was found in the code August 2017

Polyphonic Tesla Coil MIDI Interrupter
Update 25.08.2017

It was recently brought to my attention by Kilian Brixel that there is a bug in this code, where a note off status byte would be ignored if the velocity was not also set to zero.

Futurist, does this sound like a possible source of the pop's?

[futurist]

How are you playing the midi file?  And what version of the Arduino ide did you use?

Midi is played from PC, arduino version is 1.8.5

uzzors2k published a MIDI modulator back in 2013 ( http://uzzors2k.4hv.org/index.php?page=midiinterrupter ), there is a good chance that oneTesla used all kinds of public available code for their own.

I just happened to stumble upon his site and saw that a error was found in the code August 2017

Polyphonic Tesla Coil MIDI Interrupter
Update 25.08.2017

It was recently brought to my attention by Kilian Brixel that there is a bug in this code, where a note off status byte would be ignored if the velocity was not also set to zero.

Futurist, does this sound like a possible source of the pop's?

No unfortunately. Also it seems they didn't use any part of uzzors2k code

[oneKone]

So I've been thinking..... while I wait for parts for my drsstc project I might change the inverter section to a twin half bridge and have a low primary turn count.

 I think what I'm trying to achieve would be comparable spark length to a full bridge design..... Stay tuned!

[Mads Barnkob]

So I've been thinking..... while I wait for parts for my drsstc project I might change the inverter section to a twin half bridge and have a low primary turn count.

 I think what I'm trying to achieve would be comparable spark length to a full bridge design..... Stay tuned!

Just remember that twice the silicon does not give twice the performance

If you want to play it safe you should not push it more than 30-50% higher than a single bridge, if you go much higher the failure rate due to imbalanced inductance, switching times, die temperature etc, will increase dramatically.

Looking forward to see it

[oneKone]

So I've been thinking..... while I wait for parts for my drsstc project I might change the inverter section to a twin half bridge and have a low primary turn count.

 I think what I'm trying to achieve would be comparable spark length to a full bridge design..... Stay tuned!

Just remember that twice the silicon does not give twice the performance

If you want to play it safe you should not push it more than 30-50% higher than a single bridge, if you go much higher the failure rate due to imbalanced inductance, switching times, die temperature etc, will increase dramatically.

Looking forward to see it

Hahaha. I was hoping with a dual half bridge I could push more primary current?  My idea was that the parallel half bridge would share the load.. if that makes sense?

[futurist]

Steve Ward makes his QCW and Titan coil inverters like that:

i've always used individual half-bridge sections that get tied in parallel with "long" output leads to act in a similar manner to "balancing chokes" found on variac stacks, for example. There's also options for splitting up the MMC so that each output can drive its own section of the total capacitance, enforcing current sharing.

[oneKone]

Steve Ward makes his QCW and Titan coil inverters like that:

i've always used individual half-bridge sections that get tied in parallel with "long" output leads to act in a similar manner to "balancing chokes" found on variac stacks, for example. There's also options for splitting up the MMC so that each output can drive its own section of the total capacitance, enforcing current sharing.

Is there a build thread somewhere for Steve's (unless it's a joint venture build) titan drsstc?


On a side note I found this:


Build thread:
http://4hv.org/e107_files/public/1233997813_347_FT0_ctl_and_inverter.jpg

[oneKone]

So I got the driver board made and the dual half bridge fired up! Because of my not so great construction I have to completely shield the driver. Interrupted it simply doesn't work well,almost like a fade in and out of power. But it definitely works CW! With the worst voltage divider capacitors and the crappiest wiring of all time it puts out about 270mm in length of "FULL BRIDGE RECTIFIED" goodness. Once I get the correct voltage divider capacitors and the main wiring from the variac to the bridge complete I think this will be an awesome CW coil..... And hopefully an impressive isstc.       It has just occurred to me that this project will never end!