schumann resonance/ tesla
My original idea was to make a large 100,000 coil with laminated core (already done) and then to filter the signal, turn the filtered frequency into a square signal and then simply turn on and off a strobe. Now it seems I forgot all about the noise levels that could make for false triggers. On the other hand if I don't filter the 7.82Hz out then the strobe will be triggered with all kind of garbage and various strain signals and noise.
The second thought was the to filter the frequency out with the DSP. The Spectrum Lab would work fine but it introduces a significant delay (about 10sec for the narrow frequency bandpass filter I originally tried to use) and the audio buffers would add some more (although with the ULF frequency the delay introduced with audio buffers shouldn't be so noticeable and of great consequence).
Now I'm stuck with a creative block. I simply cannot think of a way to synchronize strobe display in real-time with the Schumann resonance frequency. Of course I could use some approximation but that would be cheating of the visitors of the Museum and in disagreement with the contract.
The next idea is to make a loosely stable oscillator at approximately 7.8Hz and somehow (I am not sure how though) couple it to the Schumann resonance frequency filtered by a bandpass filter in order to synchronize it. I'm not sure how to proceed because never before I had to work with such low frequencies and with such concepts as the oscillator synchronization. I do know about the phenomena but I never ever tried to exploit it in any practical way. In fact I couldn't find anything but a lot of theory and no practical ideas whatsoever.
Any help and ideas would be appreciated! 8O
This appears to be a well researched area. If it were me, I would call up some of these researchers and ask how they did their reciever:
http://nigec.ucdavis.edu/publication...project07.html
Thx for the link but I already saw it. The problem is that I only have to isolate basic Schumann resonance frequency (7.8Hz) and it has to be synchronized. Logging and filtering is relatively easy. Synchronizing part is what's bothering me.
What museum is this that has such cool displays? I want to visit!
It's the Technical Museum in Zagreb, Croatia. I also did all replicas exhibits for the Tesla Memorial Center in Smiljan, Croatia.
I had a fealing that's where it was. You shoud be proud of having real museums instead of the watered down crap here in the US. When I make my quest to the Pilsner Urqell (finest beer on earth) brewery in the Czech Republic I will have to go there too.
Well, You need to detect the schauman effect in the presence of noise. Maybe you can use some magnetic pickup technology from the music insustry:
http://en.wikipedia.org/wiki/Humbucker
You can process (DSP) the basic signal, but it is pretty low frequency so in your processing there will be a time lag while you collect enough data points to find the event. There is not too much you can do about that. Live with the time lag!
If you want to get a better indication of the event, apparently there are many harmonic frequencies generated (14, 20, 26, 33, 39 and 45 hz). If you understood the time relationship between them all, you could detect them all seperately, sum the detection outputs, and when the sum crosses a threshold, then say an event happened.
It would help if you explained a little more. Is the lightining causing a sustained sine oscillation, a exponentially decaying sine oscillation, etc?