I was trying to figure out why all of this is so familiar, and I remembered this:
http://web.archive.org/web/20070405014712/http://amasci.com/freenrg/a-vect2.html

I wrote Bill about this idea not more than half a year ago.

He didn't test it.
I didn't test it.

I think I will test it, seeing as these ideas are lining up perfectly.  I assume that I can use capacitors to tune the loop coil into longitudinal resonance?

Oh, and how do I tell if a coil is in longitudinal resonance instead of transverse resonance?  The Faraday cage and pickup coil?  Is another name for longitudinal resonance magnetic resonance?  (The reason that I ask that question is the Faraday cage will only block the E-field of 
the TEM near field region.)

Something that might be useful sometime is a list of which TEM concepts can be applied to LMD circuits--such as "pulling" the resonant frequency with a capacitor.  I'd be happy to help compile that information...we need to learn how to engineer LMD circuits as you mentioned  earlier.

I'll let you know how this turns out!

Eldarion

Hi Mark,
Going back to the phone conversation the other day about using a straight ferrite rod with one input coil and one output coil that can be slid along the rod to pick up the high nodes of the LM wave.
I will get the rod out of my box of bits and test this idea out.

So if you now try the same experiment on a torroidal core the LM wave will travel around the ring and meet the other wave coming the other way.
Will they reflect or just pass by each other?
Would it be correct to say that there is a lot more scope for a rapid build up of energy if its not absorbed by something.

If you drill a 1mm hole into the perimeter of the core and insert a 0.8mm copper wire as a probe you expect to see voltage between the probe and what?

I tried to find a supplier for that 3d7622 programmable pulse generator and could not find one.
In fact a lot of the chips seem very difficult to locate. Let me know how much they are and where you can get them from.

Regards
Rob

The reason for posting this is to show just how many resonances there are and how high the Q is in a toroidal ferrite core. *NONE* of this would be detectable without a DC bias (magnetic field in the torroid), a coil mounting that allows mechanical resonance and a square wave drive into a non-inductive drive coil... if you don?t know what you are looking for it?s very unlikely that you will ever see anything!

Look at how high the Q?s are!! .. This is a quick test and I expect that I could dramatically improve those Q values with good design. The point is that if you drive a current at one of the resonances and modulate it at another then you can get a multiplier of the Q?s ? and it will be very easy to get into extremely high energy modulation modes with significant non-linear behaviour.

I don?t know if this will yield overunity ? but It?s an area that is completely unexplored and shares a lot of characteristics with Bob Boyces and SM TPU devices.

I?ll take photographs and write a up a clearer explanation when I have done more tests ? for now I thought that it is good to give people an idea of just how significant and complicated the resonance modes can be in toroidal cores.
Please keep this confidential  to this group.



Thursday 13th September 2007.
Preliminary experiment to identify magnetoacoustic resonance modes in a ferrite toroidal core.
Mark Snoswell, mark@ballisticmedia.net

These results are with a Ferroxcube torroidal core Type T140/106/25-3C90 (140 mm OD, 105 mm ID, 25mm high).
The core has three coils that are *not* wound tightly on the core. They are loose to allow the core to mechanically resonante.

The three coils are:
DC Bias. 28 turns.
Drive coil: Symmetric Counter-wound ? 5 turns in each direction (non inductive).
Probe Coil: 3 turns.

The following resonance modes were measured with:
 4 amp DC bias current applied to the DC bias coil.
200 mill amp p-p signal driving the drive coil.

All observed resonances are dependent on the DC bias current being present. The amplitude of the resonances was directly proportional to the DC bias. There was a significant frequency dependence on the bias.

All resonances were measured with a square wave drive. Resonances could not be clearly observed with sine wave drive.
The following table denotes the number of nodes around the core at a particular resonance: resonance frequency: and Q.

The first 10 resonances (7th not observed) are for standing longitudinal magnetoacoustic waves around the toroidal circumference. The other (high frequency and one acoustic) resonant modes have not been matched with known resonant modes although the acoustic modes appears to be the fundamental flexural mode.

      Nodes   Hz   Q
      1   14,567.4   387
      2   20,277.5   711
      3   31,631.4   2228
      4   40,286.2   1857
      ~5   44,296.8   2260
      ~6   57,068.5   --
      ~7   Not observed.   --
      ~8   80,925.6   2636
      ~10   90,406.8   2659
            
            
2/3rd harmonic   1   64,305.8   3994
2/3rd harmonic   1   75,739.6   3030
            
2 nodes ?         192,913.8   4019
            
1 node?         194,599.8   3089
         227,234.8   
            
*Acoustic         8,010.8                    ~9

*no detectable signal in the probe coil but a very significant acoustic singnal.

Hi Mark,
Some good results there, how did you measure the Q value?
Were you able to move your probe coil to find the nodes?

I suppose to prove that the magna-accoustic wave is shifting you could place a dish containing some small plastic beads or water onto the core and look for the patterns while you change the frequency.

I received my sample AD9959 chips today - 2 off.
Next is to order up the AD9959 eval board.
I also have the programmable pulse chip now, so I can produce any pulse from 10ns to 250ns in 1ns steps, this coupled to the DDS 20 will give me good narrow pulses at any frequency up to 20Mhz.
I want to carry out your tests above using BB core.

Regards
Rob

I want to carry out your tests above using BB core.

Excellent -- as I will be focusing on the ferroxcube core for a while.
I will do a prelimenary test on the Micrometals core to see if I can see any simillar resonances at all -- it's a much softer core with a large poloidal/toroidal ratio which will make it much harder to see the resoances... the effects will still be there but blured out (although the lower Q's could possible make the resoances easier to see?? )... wont know untill I do a test.


Quote from IM from Rob on the pulse timer chip:
"DS1023S-100+ I got from Farnell in One in the UK, not quite as good as the one you mentioned but OK.
: Digikey sell them cheaper
: Digikey have a minimum qty of 45 at 8.19USD each
: 368 USD for 45, a bit expensive"


The DS1023s is the 8 bit programmable pulse width chip. We really want the 22 bit probrammable width chips.

Suggestion:   perhaps we can do a bulk purchace if most of us want these chips. I would be prepared to buy up to 10 of them at USD 8.19 each.

@Rob

Measuring Q ...
Measure the peak amplitude,pA at resonance F.
Measure the high and low frequencies where the amplitude is exactly pA/2
The difference in the half height frequencies = dF
Q = F/dF

WIth Q's in the 1000's you need very accurate equipment. I am borrowing a HP 33120, 15 Mhz arbituary waveform generator for these test.
Peak amplitudes are measured with the absolute voltage cursor on my Tektronics TAS 475 scope.
After determining the resonant frequency, F, and peak amplitude, pA, I set the amplitude cursor to pA/2 and find the low and high frequencies with exactly pA/2 peak amplitude.

With the equipment I have the resonant frequencies are accurate to +-0.05% and the amplitude to +-1%
The amplitude error leads to increacing errors when determining high Q's. With Q's in the 1000's my error is probably +-20% or so.

   Wonder what they would do if I walked in their front door and wanted to buy a few?   About 3 miles from them.   

thaelin