[moved] The Theremin DRSSTC Controller . . .
HV Enthusiast, Thu Jun 29 2006, 02:07AMInspired by watching an old space martian movie this past weekend, I have decided to pursue an interested project. Design a theremin device to control the output of a DRSSTC.
Stay tuned for more info. Should be a fun project!!!!
Re: [moved] The Theremin DRSSTC Controller . . .
Desmogod, Thu Jun 29 2006, 02:45AM
I know when I run my SSTC that I get capacitively coupled and arc across to anything metal. Is this going to be a problem with DRSSTC's and the theremin aerial?
mind you, being able to play "Good Vibrations" on a DRSSTC might be highly amusing.
Desmogod, Thu Jun 29 2006, 02:45AM
I know when I run my SSTC that I get capacitively coupled and arc across to anything metal. Is this going to be a problem with DRSSTC's and the theremin aerial?
mind you, being able to play "Good Vibrations" on a DRSSTC might be highly amusing.
Re: [moved] The Theremin DRSSTC Controller . . .
ragnar, Thu Jun 29 2006, 02:52AM
ROFLLES at the irony of 'good vibrations'...
...then again, I'm not sure I'd want to be waving my hand near metal plates in the close vicinity of a DRSSTC =D
...and there must be sooo many people here who don't know what a theremin is
sounds great, EVR =)
And I bet Steve is feeling left out since he posted his musical DRSSTC and started this musical trend =P hehe
ragnar, Thu Jun 29 2006, 02:52AM
ROFLLES at the irony of 'good vibrations'...
...then again, I'm not sure I'd want to be waving my hand near metal plates in the close vicinity of a DRSSTC =D
...and there must be sooo many people here who don't know what a theremin is
sounds great, EVR =)
And I bet Steve is feeling left out since he posted his musical DRSSTC and started this musical trend =P hehe
Re: [moved] The Theremin DRSSTC Controller . . .
HV Enthusiast, Thu Jun 29 2006, 03:12AM
Not sure how the DRSSTC will affect performance or operation - i'll have to build one and test it to find out for sure . . . but at the least, i'll have a way cool musical instrument to annoy my co-workers with.
In regards to good vibrations, they actually used a Tannerin, which is a varient of the Theremin in that an actual mechanical slider is used to change frequency rather than antennas.
HV Enthusiast, Thu Jun 29 2006, 03:12AM
Not sure how the DRSSTC will affect performance or operation - i'll have to build one and test it to find out for sure . . . but at the least, i'll have a way cool musical instrument to annoy my co-workers with.
In regards to good vibrations, they actually used a Tannerin, which is a varient of the Theremin in that an actual mechanical slider is used to change frequency rather than antennas.
Re: [moved] The Theremin DRSSTC Controller . . .
Michael W., Thu Jun 29 2006, 04:39AM
Strange coincidence...I started building a simple theremin this morning....EVR Do you have a schematic you are working from?
Michael W., Thu Jun 29 2006, 04:39AM
Strange coincidence...I started building a simple theremin this morning....EVR Do you have a schematic you are working from?
Re: [moved] The Theremin DRSSTC Controller . . .
HV Enthusiast, Thu Jun 29 2006, 10:38AM
There are a few reference designs i was looking into, although i'll probably modify them to my tastes before using them. Here is one that claims 20Hz to 2000Hz operation.
http://www.oldtemecula.com/theremin/
HV Enthusiast, Thu Jun 29 2006, 10:38AM
There are a few reference designs i was looking into, although i'll probably modify them to my tastes before using them. Here is one that claims 20Hz to 2000Hz operation.
http://www.oldtemecula.com/theremin/
Re: [moved] The Theremin DRSSTC Controller . . .
Michael W., Thu Jun 29 2006, 01:54PM
That link has the one that I'm making, the site includes some audio clips as well as plans for an optical psuedo-theremin. It puts out a soild square wave which can then be smoothed out into a sine wave giving a really nice rich sound...
Michael W., Thu Jun 29 2006, 01:54PM
That link has the one that I'm making, the site includes some audio clips as well as plans for an optical psuedo-theremin. It puts out a soild square wave which can then be smoothed out into a sine wave giving a really nice rich sound...
Re: [moved] The Theremin DRSSTC Controller . . .
HV Enthusiast, Thu Jun 29 2006, 03:02PM
Actually, upon further research, i may try this digital theremin circuit. It provides DC outputs on the volume and pitch control and these can easily be implemented into pulsewidth and PRF control.
Of course, i have my reservations as to whether this will even work in the proximity of a DRSSTC, but only an actual experiment will tell . . .
HV Enthusiast, Thu Jun 29 2006, 03:02PM
Actually, upon further research, i may try this digital theremin circuit. It provides DC outputs on the volume and pitch control and these can easily be implemented into pulsewidth and PRF control.
Of course, i have my reservations as to whether this will even work in the proximity of a DRSSTC, but only an actual experiment will tell . . .
Re: [moved] The Theremin DRSSTC Controller . . .
Steve Conner, Thu Jun 29 2006, 09:23PM
I guess there would be serious EMI problems since the theremin works by generating and picking up small RF currents at frequencies not too far off where a Tesla coil works. All the more reason to use what a previous poster called an "Optical Pseudo-Theremin".
Steve Conner, Thu Jun 29 2006, 09:23PM
I guess there would be serious EMI problems since the theremin works by generating and picking up small RF currents at frequencies not too far off where a Tesla coil works. All the more reason to use what a previous poster called an "Optical Pseudo-Theremin".
Re: [moved] The Theremin DRSSTC Controller . . .
Marko, Thu Jun 29 2006, 09:41PM
Even if you put yourself and theremin into faraday cage you'l still have lots of interference coupling trough cables. Best try would be powering the thing from a battery and using optical link, then caging yourself.
Without a cage coil would make an enormous 'microphony' (sort of) effect on the antennas, you may fry input HC14 chips.
When you approach it it gets even worse, since body acts as huge capacitance to the coil and just throws more of coil's electric field to the antenna, with unpredictible results.
EMI interference is actually a lesser problem, mostly it's radio frequency noise generated by sparks also helping such a circuit to go nuts.
I don't know if it is predictible to tell what will happe, depending on the reaction of the circuit, I guess it will enter an sort of 'microphony' with the coil and blow the fuse (or even worse IGBT's) with high break rate.
Marko, Thu Jun 29 2006, 09:41PM
Even if you put yourself and theremin into faraday cage you'l still have lots of interference coupling trough cables. Best try would be powering the thing from a battery and using optical link, then caging yourself.
Without a cage coil would make an enormous 'microphony' (sort of) effect on the antennas, you may fry input HC14 chips.
When you approach it it gets even worse, since body acts as huge capacitance to the coil and just throws more of coil's electric field to the antenna, with unpredictible results.
EMI interference is actually a lesser problem, mostly it's radio frequency noise generated by sparks also helping such a circuit to go nuts.
I don't know if it is predictible to tell what will happe, depending on the reaction of the circuit, I guess it will enter an sort of 'microphony' with the coil and blow the fuse (or even worse IGBT's) with high break rate.
Re: [moved] The Theremin DRSSTC Controller . . .
HV Enthusiast, Fri Jun 30 2006, 12:48AM
actually, i had some early breadboard tests this evening and it works quite well. most of the noise pick-up from the coil (which is very low duty cycle) can easily be filtered out. even the stuff that makes it through can be eliminated by putting a big RC filter on the DC output of the circuit. Since the changes due to coil operation (200kHz) is much much faster than any changes made from hand movement.
my new circuit uses digital logic running at about 5MHz and has two antennas providing PRF control and Pulsewidth control.
Time to make some boards and fine tune now . . .
HV Enthusiast, Fri Jun 30 2006, 12:48AM
actually, i had some early breadboard tests this evening and it works quite well. most of the noise pick-up from the coil (which is very low duty cycle) can easily be filtered out. even the stuff that makes it through can be eliminated by putting a big RC filter on the DC output of the circuit. Since the changes due to coil operation (200kHz) is much much faster than any changes made from hand movement.
my new circuit uses digital logic running at about 5MHz and has two antennas providing PRF control and Pulsewidth control.
Time to make some boards and fine tune now . . .
Re: [moved] The Theremin DRSSTC Controller . . .
Terry Fritz, Fri Jun 30 2006, 02:28AM
Hi,
I menitioned to Dan some digital control circuits using Theremin circuits for robot control on that other list. But tonights testing here looked like "it" would be a disaster:
Mostly for the problems Steve Conner predicted earlier.
But it sounds like Dan is reporting good results tonight and I think he is a RADAR design guy, so maybe he has "tricks" that will work
)))
The circuit Dan posted earlier has three analog filters mixed into the digital (Satanic things) that might do the trick. Mine has zero filters. But maybe the digital/analog hybrid can resist the Tesla coil enough to work!! Hope So!!!
The key is that the 4070 they use is directly filtered for low frequencies after the hetrodyne. Keeps the "slow" hand movements, while "loosing" the Tesla coil frequencies. ThereminVision filters far later (too late). Good for machine control, but bad for Tesla coil noise. You "might" have to use a second order filter, but it depends on the range you need... I think Dan's can use "slow" DC and synthesize back to the audio range from there, so he just throws out the middle man noise.
Cool!!!
You will need TVSs in parrallel with the timing caps on the input. They will do no harm since the frequency shift from the little added capacitance just adapts. I think they are a don't care for the 4093 input compared to 22pF, but the 4093 inputs just don't like "shocks". With a well placed TVS, they might take a direct hit, in your dreams :o)))
Cheers,
Terry
Terry Fritz, Fri Jun 30 2006, 02:28AM
Hi,
I menitioned to Dan some digital control circuits using Theremin circuits for robot control on that other list. But tonights testing here looked like "it" would be a disaster:
Mostly for the problems Steve Conner predicted earlier.
But it sounds like Dan is reporting good results tonight and I think he is a RADAR design guy, so maybe he has "tricks" that will work
)))The circuit Dan posted earlier has three analog filters mixed into the digital (Satanic things
) that might do the trick. Mine has zero filters. But maybe the digital/analog hybrid can resist the Tesla coil enough to work!! Hope So!!!The key is that the 4070 they use is directly filtered for low frequencies after the hetrodyne. Keeps the "slow" hand movements, while "loosing" the Tesla coil frequencies. ThereminVision filters far later (too late). Good for machine control, but bad for Tesla coil noise. You "might" have to use a second order filter, but it depends on the range you need... I think Dan's can use "slow" DC and synthesize back to the audio range from there, so he just throws out the middle man noise.
Cool!!!
You will need TVSs in parrallel with the timing caps on the input. They will do no harm since the frequency shift from the little added capacitance just adapts. I think they are a don't care for the 4093 input compared to 22pF, but the 4093 inputs just don't like "shocks". With a well placed TVS, they might take a direct hit, in your dreams :o)))
Cheers,
Terry
Re: [moved] The Theremin DRSSTC Controller . . .
HV Enthusiast, Fri Jun 30 2006, 03:49AM
Additional testing has yielded some problems. I may go with an optical version instead. Although, i'll have to figure out a way to cancel out the effects of ambient light. Should be interesting . . .
HV Enthusiast, Fri Jun 30 2006, 03:49AM
Additional testing has yielded some problems. I may go with an optical version instead. Although, i'll have to figure out a way to cancel out the effects of ambient light. Should be interesting . . .
Re: [moved] The Theremin DRSSTC Controller . . .
Terry Fritz, Fri Jun 30 2006, 04:43AM
Hi,
While Dan is fiddling with his Theremin, check this out:
Cheers,
Terry
Terry Fritz, Fri Jun 30 2006, 04:43AM
Hi,
While Dan is fiddling with his Theremin, check this out:
Cheers,
Terry
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