Was just reading this on wikipedia:

"Resonant circuits exhibit ringing and can generate higher voltages and currents than are fed into them."

hi all i read the pdf by Ossie Callahan that was just posted - very interesting - I would suggest simply filling a cap of say 450uf 450VDC rated from any ringing you might find happening in a motor coil, rather than the 5  dead batteries in series like he does.
try differnet cap sizes to find what will work best for you...

SWITCH-OUT the backemf into the cap - one way is FWBR AC legs across your motor coil, and/or switching for motor coil, and then DC side of FWBR into cap.
Then put a switch somewhere on this FWBR - for examnple in series on one of hte AC legs (would need to be bidirectional here since its AC being switched) or you cna bput swtihc on DC side of FWBR too...

Time this backemf swtich to turn ON just AFTER the motor coil switch turns on and time the backemf swtich to turn OFF just AFTER the motor coil swtich turns OFFf- say a 5 degree delay....

now whenever this backemf swtich is OFF, and hte motor coil swtich is OFF too,  that is good time to dump the cap into a load, since it will be totally isolated then.

Now there is another collapsiing-negatieve peak that occurs too, after the motor coil pulse, and after the backemf swtiched-pulse to fill cap, and also will be after the cap discharged-to load pulse too....

this is that neg peak I was telling Chamalad a couple weeks ago he should SHORT at this neg-peak seen in his scope shot, and this neg-peak short will  fill up cap even more - and this shorting-at-peak short will create oscillations/rings  that resemble what Osside does with reed swtich is what I am getting at.

Short-at-peak this neg peak by having AC legs of another FWBR across the motor coil leads, which then  has its AC legs SHORTED straight across with bidirectional mosfet switch  (not a swtich in series like the backemf swich is on one AC leg) ... DC side of FWBR goes into same cap, or 2nd cap if you want.

s mentioned, the shorting-event of this neg peak will send that coil into ringing osicllations, similar to what Ossie does with his "hyper-ringing" reed swtich...

so you have done four things, fire the motor coil with a pulse to move rotor around, recover the backemf/recoil of the coil into DC cap, and also have shorted the coil at a "sinewave" (negative) peak into DC cap too, and finally have knocked this cap into load when everything is turned OFF/disconnected too, so the cap hittling load will not reflect back as additional draw (non reflective)

Hi all

After playing a lot with my gen coil i finally got it in resonance. The coil screams when i put a 0,22uF cap in paralel. The rpm is around 3400 and gets down with no more than 10 rpm when in resonance.
I did another test too. 
I tooked another coil (smaller) and moved it around the rotor to see if i can get some mV. Above the gen coil i picked around 2V unloaded. I connected a small led and it got lit.
Then i connected the cap to the gen coil.
With the gen coil in resonance i picked 0.5V more in the coil above witch had the led connected.(led lit a litlle more)

In my current setup i have 6 driving coils and (for now) 2 gen coils( i must make other 18 gen coils) . These 2 gen coils sits one in top of the other. When i put one coil in resonance , the voltage of the other coil increases too. Then the coil allready in resonance increases voltage when i put the other coil in resonance.
So it's seems that if i could have all 18 coils (ready and mounted in resonance) the ''resonance effect'' could do something interesting. For now i'll go back and try to make some other coil.

   I am in the process of wiring up my ten coiler. A bit of a variant but the nine/eight showed a lot of promise so added one more coil. This way I can trigger off one source and eliminate the cross wires. Each half will be independant of the other and linked by the mounting rods.
   I have decided to use bifilar coils that can be used any way I choose. Glue takes so long to set up good but have to wait for it. More later

thay

LC meter replacement finally arrived. The resonating coil is 0.88mH. Unifilar.