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Audio Frequency modulated interrupted solid state teslacoil

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LAN_403

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Thu Sept 21 2006, 08:41PM

Registered Member #76 Joined: Thu Feb 09 2006, 10:04AM
Location: Hemer, Germany
Posts: 458

yeah, i made a few experiments today and came up with some impressive results, . after building a musical drsstc interrupter i decided to develope a codec for interrupters to use normal analog audio signals to generate the off time pulses. cause the complexity of the signal does not allow drsstc duty i decided to build a normal isstc to let the sparks do its job, producing music. i use my hardware synthesizer and a midi keyboard to produce a squarewave with delay,reeverb etc. then this signal is fed into a simple circuit which modulates the squarewave to 50ys on impulses and off time pulses, representing the frequency of the sound. i can use every audio signal including whole songs etc but the quality is very bad due to total overranging the maximum of 17000bit/s too many "overlapping" and damped sounds,so i decided to improve the circuit for simulating an e guitar which works perfectly

here is me with my keyboard

and here is the signal of the interrupter fed into a normal amplifier to let me hear what the isstc would sound like

sorry for the bad quality , the trigger does not do its job with this whole lot of different time sequences, but hopefully you can see in some frames what the trick is. when i play 2 different sounds, the off time generating the sound is changing between the one and the other sound, so i have a balanced chord, hopefully someone can understand what i mean

when the interrupter interrupts the hf pulses from the secondary in the same way like in the video, the isstc would sound the same, producing a whole lot of interesting sounds especially a real plasma e guitar sound

. tommorow iÂ´ll build a simple isstc to test my interrupter on it and hopefully it will sound like this in a special way

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Sat Sept 23 2006, 10:03PM

Registered Member #76 Joined: Thu Feb 09 2006, 10:04AM
Location: Hemer, Germany
Posts: 458

maybe everyone of you thought that this thing could not work or something, dont know, but it works, here it is. its just a simple sstc interrupted with the signal i showed you in the video with the oscilloscope

with this little circuit and the hardware synthesizer it is possible to play some sort of instruments polyphonic. its the first audio interrupted solid state teslacoil from what i know, and it has a very special sound,.. with this technique it is possible to modulate a drsstc to play music! not like a pc speaker, someone said this in the omg musical drsstc thread, ..now the day is not too far away for the first audio modulated drsstc

Marko

Sat Sept 23 2006, 11:05PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

My class E thread got ignored and I lost my posting will

That looks great and I really hope to see (hear) it on a big DRSSTC soon!

Technicsally, to really play music with a DRSSTC you would just need to push PRF over audible renge and then PWM it (still having a questionable quality) You are doing practically same on lower frequency so it sounds 'bangy'. I think I mentioned something like that in steve's thread.
Coil looks nice also.

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Sat Sept 23 2006, 11:38PM

Registered Member #76 Joined: Thu Feb 09 2006, 10:04AM
Location: Hemer, Germany
Posts: 458

yeah, but you cant push a drsstcs off time over audible range, thats why i used a isstc which works great. i had a new idea by pwm the on time while the off time is still the same in a range that you cant hear anymore (20khz or so) so the duty cycle will change by varying the on time so varying the streamer lenght, producing sound, but even this wont work with a drsstc. simple pulse width modulating the off time does not work with good quality, i tried this, the lower frequencys in a song, baselines etc causes a off time over 5mS and more, disabling all higher frequencys within this time, the quality goes crap. the only possibility i see is using a on time with just 5ys or so and a very high secondary frequency to get the cycles you need to produce decent streamers, the off time will stay the same all the time in a range that you cant hear (20khz so 50yS) the on time is changing with the audiosignal in a range from 0 to 5 ys so you have a maximum duty of 10% (maybe that could allow drsstc duty)

Marko

Sat Sept 23 2006, 11:47PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

The 20Khz thing was rather a hypothesis, You would probably have to make a very high frequency (class DE?) DRSSTC and I don't believe it would give bigger arcs than a CW SSTC of same power.

Maybe in couple more years when IGBT's get faster or HV mosfets get significantly lower Rds ON..

...

Sun Oct 01 2006, 07:06AM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

WOW, That is really impressive!

Was the sound if the first movie actually coming from a isstc? I would have liked the viedo of the streamers from that...

Me wants a 10kw drssc (or istc) with that... Could do a frigging concert!

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