Overunity Parametric Oscillator?

[giantkiller]

You would to match the tank frequency to a harmonic of the resonate freq of the transformer core. Its like the opera singer breaking a glass with their voice.

[Sprocket]

Well, I gave it a go.  Both primaries = 350mH. Tried it with 1, 2 and 4.7uF caps.  Used a relay to short one of the primaries, energised by my old pulse generator.  The relay probably manages ok up to about 150HZ.  No lovely sine-waves I'm afraid but it does produce a amplitude modulated rough 200HZ sine on one of the secondaries, up to a max of about 100mV.  I'm assuming the 200HZ is just a harmonic of the 50HZ mains.  I expected to see nothing at all so it wasn't a total loss...

[nul-points]

hi Neptune & Sprocket

could you guys either post schematics or links to such of the circuits you're experimenting with?

if you're using AC excitation of the LC elements then the L & C components need to be resonant at the drive freq(s)

eg at 50Hz, with 350mH (combined) primary, then C should be approx 29uF for resonance

thanks
np


http://docsfreelunch.blogspot.com

[Sprocket]

I just tried what neptune suggested, namely 2 MOT primaries in series, and in parallel with a capacitor, then short one of the primaries with a relay and monitor either of the secondaries.  No AC excitation involved, just a plain-vanilla parallel LC circuit whose resonant frequency I calculated at about 269Hz, so as per neptune's theory, shorting it at half that might produce interesting results.  It didn't, but at least something was happening which surprised me especially as there was no attempt to inject any waveform into the transformers.  With the 50Hz 'hum' everywhere, I would have expected to see this (if anything) on the secondary, instead I see a 200Hz AM-signal which varies in both amplitude and frequency - the modulation, not the 200Hz - as I adjust the rate the relay is being switched at.

[nul-points]

No AC excitation involved
...
a  parallel LC circuit whose resonant frequency I calculated at about 269Hz, so as per neptune's theory, shorting it at half that

ok, thanks Sprocket

my reading of the JLN Parametric Osc experiments (eg. v4, say, courtesy of Fred Apps), 

   link:  http://jnaudin.free.fr/html/params40.htm

is that both an input signal plus a switching signal is used

also, note that the suggested  switching freq is 2x the LC res freq. - not half, as in your latest test


hope this helps
np


http://docsfreelunch.blogspot.com