Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx> Hi again Dan,I tried the ThereminVision II digital robot controller near the SISG coil. The readback signals were totally scrambled. No lasting harm done. I feel there is little hope there... The D-FlipFlop heterodyne circuit will pick up the coil's fundamental like crazy and the digital filter is just an average circuit that will rip at super high speed near a coil. One "might" be able to program the noise out with the microcontroller, but that is a far reach... The fundamental frequencies of the sensors are about 2MHz but all the digital electronics has nothing to "filter out" the coil's powerful oscillations as they get mixed in too.
The circuit did go up against a handleld Tazer armed robot in a competition and did fine until the Tazer "connected" and knocked out three sensors (150kV vs. 555 timer input pin...). But those signals must be a single sharp HV spike that just did not register RF wise, unlike a heavy oscillating DRSSTC signal. But the poor crippled robot did win due to human error latter :o)))
I did not try the Moog Theremin since I am not sure how well protected it is and I did not want to risk frying it. But just the "noise" should play havic with the amplifiers in it at any rate. The antennas for pitch and volume are direct connected to the "guts". I think there is a schematic for it on the net "somewhere".
So I am afraid that I can't help much, and it basically looks very "bad" :-( I am sure a Theremin type circuit "could" work, but it would be difficult and just off-the-self ones are probably hopeless.
The big problem is to measure the sub pico-Farad effects of ones hand near the antennas while that 350kV ~150kHz DRSSTC monster is playing 15 more feet away. Theremin circuits use fairly high frequencies close to the DRSSTC, so "filtering" is almost impossible.
The are optical versions of the Theremin that may have much more hope, but I am not familiar with them.
Hope this helps, or at lest is a clue to the problems that await.
Cheers,
Terry
Hi Dan, There is a digital solid state and public domain theremin version here: http://thereminvision.com/version-2/TV-II-index.html http://thereminvision.com/version-2/ThereminVision-II-manual.pdf You can wire the basic circuit on a breadboard in about 1/4 hour.The problem will be that the capacitance antennas will pickup the voltage off the top terminal of the coil just like a length of wire or plane wave antenna:http://hot-streamer.com/TeslaCoils/MyPapers/planant/waveant3.htmlYou can easily model the thing in microsim to determine how bad that will be. You will want to add a TVS across the antennas to ground for sure which will not affect the function.The voltage off the coil will appear as a valid signal but might very well be cancelled by the counters and anti-jitter stuff. Probably not to hard to filter for relatively low speed hand movement in this case.I have digital demo board of the above and a Moog theremin I could try out if you need. I would think the digital version would be vastly better.Cheers, Terry At 08:55 PM 6/28/2006, you wrote:Watching an old sci-fi martian movie this past weekend has inspired me to explore the possibility of using a Theremin device to control the output of a DRSSTC system. I plan on designing a system which can independently control both pitch (PRF) and arc length (volume) of the DRSSTC by simply moving your hands around the Theremin device. The only question mark is how it will interact with the fields generated by the DRSSTC itself. That i won't know until i actually build the device and do the testing. I'm keeping my fingers crossed, so if it works, itwill be pretty damn sweet!For those who don't know what a Theremin is, here is some information here on it:<http://en.wikipedia.org/wiki/Theremin>http://en.wikipedia.org/wiki/Theremin Dan