STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM

[broli]

Well, if you think about any coil on a relay, which way is the shunt diode that SHORTS the fly back?

Hmmm... it's not in the direction of the initial current flow.

I have been in electronics for 30 years.... I probably have an idea. I have a two oscilloscopes also and can set it up to look like anything, but the term fly back IS exactly what it means.

If you can't see that 1+1=2 then there's little reason to argue. If we don't have a mutual understanding of basic things we will never achieve anything.

[hartiberlin]

Stephan:
.....

The real issue underneath all of this is that it takes electrical energy to saturate the coil.  You can see it in the Steorn clip and K4zep's clip.  The real question is is the electrical energy required to saturate the coil more or less than the rotational energy added to the rotor when the magnet flies by the toroidal coil?  That is the key critical question and I haven't seen any discussion about it around here.

MileHigh

Yes, you are totally right...
BUT you can extract about 90 % of the inputted electrical energy via BackEMF extraction.
Then you have almost the rotational energy due to the attraction of the magnet to the ferrite core FOR FREE !

Then the attraction energy must only be bigger than the 10 % you will not be able to
extract via the BackEMF extraction circuit.

The simplest BackEMF extraction circuit is just a graetz bridge across (parallel ) to all the toroidal coil in series
feeding a capacitor.

[mondrasek]

Isn't it wonderful what civility and knowledge can do?

Gentlemen, (and I ask many to re-read that last word) I applaud you!

Please continue posting your findings!  Cool stuff!

M.

PS.  TK, would you kindly join in here?

[hartiberlin]

Hi Stefan,

Spun motor up to 1000 RPM @ 26VDC give or take.  Removed power,  scope shot directly across coil, 20mv./div.  50 to 60 mv peak funky sine wave due to imperfect magnet placement (shaky hands and eyeballs).  IF all 4 coils were balanced, I assume they would disappear. When I rebuild it, I will try to balance to less than .1uH. Lets see 60 mv back emf vs. 26 volts not bad.  Hope this helps.

Respectfully,

Ben

Hi Ben,
many thanks for the scopeshot !
Well , now we know, that with a good setup this will work.

60 mV with so many coil windings on neodym magnets is pretty low
at almost 1000RPM.
If you would take a normal coil with the same number of windings
and would use it, the induced voltage would be probably a few volts,
so we can say that the motor to generator effect is very asymmentrical,
what we also need for an OU motor.

So it seems the toroidal coil does not work well as a generator
and so the counterEMF(induction into the coil while motor is running)
is very much suppressed which
is a very good sign that this motor is just a motor  and not a generator.

This way it can be designed as an OU motor with stronger magnets  and the
right mechanical and electrical setup with BackEMF extraction and short gap magnetic
flux pathes.( low magnetic flux losses)

[hartiberlin]

Hi Ben,
could you please put a graetz bridge rectifier bridge across your toroidal coil and charge up a big cap with it during the motor runs ?
Would like to see the produced voltage and the cap uF capacity.
Many thanks.
Regards, Stefan.