Shadow,

Very smart design in the resistor. I guess you have to use two resistors in parallel, one for each row of electromagnets, N and S, in order to achieve two sinusoidal waves, one in each row. Am I right?

If you use two parallel resistors you could better test with a sawteeth shape instead of the sinusoidal shape. With a sawteeth pattern in each row you are always keeping the same total current in the system  (I_north + I_south = constant)

Although in the patent is only drawn one resistor, I tend to think that Figuera maybe used 2 resistors in parallel in order to have a simetrical wave along one whole revolution of the commutator. Remenber that in the patent is written: "the resistor system is sketched in a simple way  to make easier its understanding"

Regards

This may be a silly question, but what's the diffrence between soft steel and soft iron? I have  a vague idea that you refer to carbonized iron, but in terms of remanence I guess that is only a problem of hardened steel, no? I would also guess a tiny socket remanence won't kill the effect, since the EMF will be much stronger than that.


From what I've seen with "iron" screw rods, zinc coated (most likely impure iron), there is a Remanence that can even hold an attached 1mm nail, but the field is altered with no problems.


One thing you may have to worry about much more is basic Reluctance / permeability. All smart flux path ideas won't work when the field strenght is near zero even before it reaches the secondary.


If I was you, I'd surf to ebay and order some Metglass with that insane permeability, virtually allowing you to build fancy cores trough the livingroom of your neighbour and back, and not lose any significant field strenght on the way, not even at high frequencies. Check the various subtypes, I guess on metglass.com. These are 21st century hightech materials. Seen for 45$.


Regards

this is a similar circuit you might want to watch, possibly where one idea might be a trigger to another on same lines.  >  http://www.youtube.com/watch?v=cD_Bwwvlc3I  <

Dieter;

you answered the question your self, yes Iron has very low carbon content and steel has a high carbon content.

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SOLID STATE TIMING BOARDS

PS. I just sent off to have my Timing board Professionally made for figueras device but i will have Three extra boards available if  any one wants them,had to buy a 4 pack bundle. they are 8 volt (5v to chips) 9 channel boards like Patricks design but very optimized in a 5.95 x 4 package.
the pic below is what you will get (without Parts board only).

That board is looking great, but I guess you'll have to add cooling ribs.


About the steel issue, so carbon is a problem ? What exactly is it?


Wouldn't it be sufficent to use a low remanence material for the Y core only? And to prevent Hysteresis, does it make a difftence wheter steel or iron is used?? I'd rather try laminates, or ferrite, or sendust or otherwise iron sawdust casting.


But I repeat, even a core made of iron wire has a poor permeability, making any efforts very fruitless, where a ferrite core of good proportions, or even metglass or permalloy makes things way easier. A good core permeability is as important as a good enameled wire.


Regards