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Author Topic: Daniel McFarland Cook Generator  (Read 90032 times)

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Are we missing something ?

I have copied an excerpt from a newspaper article printed in 1886 by the Cincinnati Commercial Gazette.


 " Some months later the Cincinnati reporter was invited to Cook’s shop where he had to sign an agreement not to reveal the secrets he was to witness.


The writer noted that Cook worked in a stable with a horse in the next room, and continued, “The machine was rudely constructed for Mr. Cook made it all himself with a few old tools that had done too much service already. Parts of it were made of wood and the whole was put together in a not very artistic manner.”


“I tested the current in several ways and found it very powerful. Having made electricity somewhat of a study, I was surprised at the simplicity of many of the principles. The manner in which he expects to get the results is theoretically correct and there is no mechanical difficulty which he has not already overcome.”


“After examining this machine carefully in all its parts I was conducted to an adjoining room where, on a table, sat a smaller model of more accurate make. It contained a much better arrangement of the parts, and from what he showed me I am compelled to believe all that Mr. Cook had told me.” "

By now I think most who have studied this patent, the pairs of coils were probably bought from Davis's.

The reporter mentions machine, obviously there's more to the device than the patent drawing shows.

So, what if we were to put an interrupter in the circuit ? A simple attracted armature that oscillates between the two coils.  Rather like the old telephone bell ringer but substitute the bells for contacts ?   

Just a thought that occurred to me the other day after reading another article on D McF Cook's flying machine.

Cheers Grum.


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Nanny state ? Left at the gate !! :)
   

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I think you are correct. It was understood that induction coils came with an interrupter, otherwise they would not work. There was no AC in those days. (1880s). There would be no point in even mentioning the interrupter in the patent.

http://www.sparkmuseum.com/INDUCT.HTM


Going forward to 1915, Benitez DID put an interrupter into his patent because by that time AC was common place.

I've just remembered that when I had my freak result with a MOT the solder joint was dry and it obviously created an interrupter of sorts.

My 2 pennies worth.


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VAR is just an angle on a scope. Nothing to see here -  move on.
   
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I'm glad you found that article and the same conclusions as I found. Unfortunately McFarland patent was tampered not only by removing the missing circuit but also by not mentioning the correct "modus operandi" and so on... Keep digging
   

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I'm glad you found that article and the same conclusions as I found. Unfortunately McFarland patent was tampered not only by removing the missing circuit but also by not mentioning the correct "modus operandi" and so on... Keep digging

Dear Forest.

I could do with some kindly soul donating one of these !! " Bell Set No 50 C "

I scrapped hundreds of these along with telephones during my time on the " Comms " section, now amazingly collectible !!

Cheers Grum.


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Nanny state ? Left at the gate !! :)
   
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It's turtles all the way down
A study of the efficacy of certain types of long coils over short squat coils would be worthwhile in the Cook endeavor. There might be a magnetic cascade effect with small input currents in the long coils.

Long coils were used in early dynamo electric machinery at the turn of the century due to their high efficiency.

The textbook formulas for iron core coils (especially very long ones) does not address the possibility of a domain cascade or avalanche effect, as far as I know.


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Just because it has a patent application or is patented does not always mean it really works.
   

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A study of the efficacy of certain types of long coils over short squat coils would be worthwhile in the Cook endeavor. There might be a magnetic cascade effect with small input currents in the long coils.

Long coils were used in early dynamo electric machinery at the turn of the century due to their high efficiency.

The textbook formulas for iron core coils (especially very long ones) does not address the possibility of a domain cascade or avalanche effect, as far as I know.

Dear ION.

Is this the scenario to which you are referring ?

http://jnaudin.free.fr/dlenz/DLE22en.htm

Depending on the operating frequency a number of nodes will appear along the core.

Cheers Grum.


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Nanny state ? Left at the gate !! :)
   
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Dear ION.

Is this the scenario to which you are referring ?

http://jnaudin.free.fr/dlenz/DLE22en.htm

Depending on the operating frequency a number of nodes will appear along the core.

Cheers Grum.


Coils made from insulated iron wires :-)
   
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It's turtles all the way down
A study of the efficacy of certain types of long coils over short squat coils would be worthwhile in the Cook endeavor. There might be a magnetic cascade effect with small input currents in the long coils.

Long coils were used in early dynamo electric machinery at the turn of the century due to their high efficiency.

The textbook formulas for iron core coils (especially very long ones) does not address the possibility of a domain cascade or avalanche effect, as far as I know.

I was referring to ordinary iron core coils wound with copper wire and the iron core having a large length to diameter ratio, as in early telephone relays or dynamo-electric machinery as in the attached.


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Just because it has a patent application or is patented does not always mean it really works.
   
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With short coils you cannot make use of the high permeability to get high flux at low current.  But with long coils you can.  So if you want maximum flux at the pole face for minimum current, hence minimum resistive loss, you use a long coil.  It all comes down to the demagnetization factor.  My paper "Energy around coils and magnets" tells you how to use Nagaoka's factor as the demagnetization factor for permeable rods.  Don't have it to hand at the moment as I am away in our motorhome (RV if you are American).

Smudge
   
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It's turtles all the way down
With short coils you cannot make use of the high permeability to get high flux at low current.  But with long coils you can.  So if you want maximum flux at the pole face for minimum current, hence minimum resistive loss, you use a long coil.  It all comes down to the demagnetization factor.  My paper "Energy around coils and magnets" tells you how to use Nagaoka's factor as the demagnetization factor for permeable rods.  Don't have it to hand at the moment as I am away in our motorhome (RV if you are American).

Smudge

I was merely musing on the idea that a very long iron core wound over with copper wire in the most efficient way could be very good generator of flux, and as such there could be a domain avalanche effect at some critical size, even with a small current input. Cook's coils were supposedly over three feet long and worked best with a core of small diameter iron rods. In other words, is it possible with such a long magnetic structure that flux would suddenly non-linearly increase  to saturation at some relatively small value of input current?


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Just because it has a patent application or is patented does not always mean it really works.
   
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I was merely musing on the idea that a very long iron core wound over with copper wire in the most efficient way could be very good generator of flux, and as such there could be a domain avalanche effect at some critical size, even with a small current input. Cook's coils were supposedly over three feet long and worked best with a core of small diameter iron rods. In other words, is it possible with such a long magnetic structure that flux would suddenly non-linearly increase  to saturation at some relatively small value of input current?
I am sure there is such an effect.  There will be a propagation delay along the core and with a fast enough rise time of the input pulse that delay will be seen in the manner in which the flux rises.  The long core can be considered as a form of transmission line.  But it is a transmission line working in the magnetic domain.  From the classical point of view it is a transmission line having a reactive characteristic impedance.  I have used classical theory to show that such a line, when terminated in a reactance, exhibits negative input resistance that can lead to self oscillation.  So IMO there is something of substance in your musing.

Smudge
   
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