Stubblefield coils (bifilar) and speculations

[FatBird]

You might try a capacitor in series with the meter to see if the output is AC or DC.  If you still get a reading through the cap, then it is AC.




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[Localjoe]

@RStiffler

my appoligies for past incidents since then ive purchased acne cream and a new brain.

Great EE lesson!  In our ongoing project it will be very advantageous to have the impedance calculations for different sets of the primary and secondary coils.

When I say sets I mean a primary coil consisting of cloth insulated copper and bare iron or steel wrapped in a bifilar fashion around a soft iron bolt as a core that insulated with cloth as well from the wires.  The secondary as well call it is a single wire of thin magnet wire enameled wound on a spool  placed on the outside of the primary coil body. 

This device is self actuated by a relay or suitable device of interposition to make and break the connection between the primary wires of copper and iron.. A mini rotary spark gap or relay should do.    For this device to produce usable ac power at a frequency we desire im assuming were going to have to wind the secondary in a 1/4 wave fashion After finding the speed at which to run the rotary gap or relay.  We were tossing around the idea of a small motor with a pot or rehostat in line for speed control and a wooden or plastic disk with metal contacts on it proportioned evenly in 90 degree or 45 degree segments.

Im not any kind of expert when it comes to the math end of this so the moral of my story is this once we figure out the different coil's impedances plot them on a table what would i do to calculate a resonate length for my secondary at a given frequency.. I was going to use one of the tesla coil calculators but i figured id ask a smart rf engineer like yourself first and all the tesla coils were air core not metal so i know theres and additional calculation in there somewhere.  Its confusing me because the ends of the primary coils wires the copper and iron remain in the ground or not touching anything, this is said to preserve the character of the electrodes, the other two ends are the ones hooked to the relay or rotary gap plus they produce their own power its not pulsed or powered in any way so im at a loss to draw a real diagram.  

looking at the operation of the device ; when shorting the terminals of the electrodes breifly which turns the central bolt into an electromagnet. The pat states a magnetic feild is produced within and outside the primary coil so the bolt on the inside and the secondary on the outside the primary coil. The action of the rapid collapsing of the magnetic field in the central bolt must play some part to the action of this transformer im assuming the feild componet on the outside of the primary coil is waht produces the power in the secondary so im curious to the inner field puropose.

                                                                            Thanks for taking the time to read this and for your expertise
                                                                                        again sorry about our past encounters 
                                                                                                                                  Joe
                                                                                                                                 

[mthompson]

can you  explain a little more about how to go about this ?

I have played  with the idea a little  but  havn't got  anyhing to work  so far .

My  goal  for   the " core" part of the  battery is  a couple volts  and  maybe a  hundred  or so m A
AC  would  be ideal ....... DC makes things a bit harder .

One of my reasons  for  trying the Tesla  pancake  type winding  is because if it works  it would make a " modular " stubblefield  cell .........just  build and stack  untill you  reach the right  power  level.

I am  still undecided   about   how well  it works mostly do to the wiring    there  are many  posabilitys  .....  sometimes changing  one wire and the voltage across the whole thing drops almost to nothing .gary   

Gary:  My interest in the Stubblefield battery device is somewhat indirect, being founded primarily in curiosity about those aspects of its design which don't seem to make much sense from the view point of designing a straight forward electrical generating device. The logical explanation would seem to be that these somewhat inexplicable design decisions where made because they are functional in regards to integrating into any system Stubblefield might have developed to tap into telluric electrical currents. The battery probably holds an important position in all this, but it doesn't provide all the answers. So, my principal interest is in following jeanna's and the others' explorations as they try to figure out just what Stubblefield might have been doing in order to create a functional earth phone system among other things. For instance jeanna's idea of looking at the batteries from the view point of wiring for transistors is rather amazing. Nothing may come from it but that is the type of enquiry that eventually produces results.

In regards to possible thoughts on how the single wire capacitance current process might be applied to the Stubblefield battery; it was looking over my original thoughts on that which has caused much of the delay in responding to your question. I think it can be done, but it might be more helpful first to take a look at more basic concepts, such as those wiring questions - my apologies to all if this turns out to be too long and simplistic to be of any assistance.

Stubblefield was, on one hand, very explicit in his patent, and on the other, probably some what deliberately ambiguous. For instance, he is very straight forward in stating that the battery is designed as a voltaic couple that produces electricity through the electrolytic process that occurs between dissimilar metals. He also straight forwardly states that by using bifilar coils instead of plates the electricity can be directed to flow through the coils through a make and break switching device which will turn it into an electromagnetic transformer which will provide useable electrical power through a secondary coil. Nothing wrong there.

However, when he describes the actual method of wiring the circuits things get vague. For instance, when he refers to the coil terminal ends to use for the external circuit to the switching device he simply calls the copper wire 5, and the iron wire 6. Two ends are simply clumped together and referred to as the terminals 10:

"The terminals 10 of the copper and iron wires 5 and 6 are disconnected so as to preserve the character of the wires as the electrode of the voltaic couple; but the other or remaining terminals of the wires are bought into contact through the interposition of any electrical instrument or device with which they may be connected to cause the electric currents generated in the coil-body 4 to flow through such instrument or device."

To understand why this is not only being ambiguous but deliberately misleading it helps to look at the circuit for a regular voltaic battery. Voltaic couples were traditionally constructed of alternations of dissimilar metal disks in an electrolytic solution. Each pair of dissimilar plates is referred to as a cell. Each cell creates a voltage potential based upon the electrical differences between the two metals. Stacks of these cells are in series so the voltage increases as more cells are placed on the stack. The internal electrical circuit consists of the electrolytic activity between the plates. The external electrical circuit consists of a metal conductor connected to the top plate of the stack and running to a connection to the bottom most plate - pretty simple.

Stubblefield's design however is not so simple or straight forward because it is a multi-purpose device. It consists of a bifilar coil with each of the two coils made of dissimilar metals. In this design the bifilar coil is a cell, and each coil is the equivalent of a standard plate. Just like a standard voltaic battery electrolytic action between the dissimilar metals produces an internal electrical circuit. An external circuit can be created by making a connection between the two coils anywhere on their surfaces. So far so good.

Things start getting complicated in regards to the electrical circuit for turning the coils into an electromagnet. The reason for this is because unlike a standard voltaic battery circuit, now exactly where the connections are made becomes critical. As this is a single cell both coils must be utilized, and they must be connected so that the current flows through both coils in the same direction in order to create a unified magnetic field for the electro-magnet. Stubblefield says that in order to accomplish this the two #10 terminals must be connected together.

"By connecting the #5 and #6 ends of the iron and copper wires through a Make and Break device, and directly connecting the #10 iron and copper ends, a closed curcuit is created through which the current can flow, creating the electromagnetic field, and allowing for the powering of a secondary coil, the electrical output of which can be tailored to need by its construction." **(edit: this was a mis-quote and Stubblefield did not say this.)

Here is one of the examples of his somewhat mis-leading descriptions. A quick reading of the patent leaves most with the impression that the 'terminals 10' pair are at one end of the coil wraps, and the 'remaining terminals' are at the other end. This isn't so. There is no logic to the nomenclature Stubblefield used here to designate the coil wire ends. It would have been logical to use something like numbering the copper terminal at the beginning as say, 5a, and its corresponding iron terminal 6a. Then the two at the further end could be identified as 5b and 6b. Using this terminology the 'remaining terminals' used for the primary make-break circuit mentioned could be designated as being 5a and 6b, while the 'terminals 10' pair would be 5b and 6a,.

Looking at the diagram, it can be seen that this wiring scheme is logical from the view point of creating an electro-magnet. It is also just as obvious that it is a disaster from the perspective of the proper operation and maintenance of a voltaic battery. While the primary, 5a-6b, circuit can be held open by the switch, a direct connection between 5b-6a is nothing less than a 'dead short'.

To make a long story short, lets just say that Stubblefield, while calling for a connection between 5b-6a, does not stipulate the type of connection, nor its duration. With that in mind it becomes somewhat logical to imagine that the 5b-6a connection, just like the 5a-6b, is not a direct connection but rather a switched connection. Whether both are made and broken at the same time, or if they alternate is an interesting question. A synchronized operation provides for a pulsed direct current, while an alternating current is produced other wise.

I think that is about the most interesting observation I've had time to make.

In regards to methods for creating multi-cell Stubblefield batteries, I think its possible, but perhaps overly complicated as each connection between the dissimilar coils would seem to have to be through a switching mechanism otherwise a 'dead short' condition will exist in the voltaic circuit.

Using single-line capacitance current methods are a possibility, but again, probably overly complicated. Basically you'd be looking at using capacitors of one type or another at the coil free ends - unless you could design the coils so their inherent internal capacitance would be adequate. Tesla certainly designed such coils but I have no idea of how to go about it.

One last thought: As mentioned above, the electrical connections for a voltaic circuit is different than that for the electro-magnetic setup - any contact between the two dissimilar metals at any point on their surfaces suffices for the voltaic battery effect, and that includes contact between the copper coils and the iron core. The core is in the electrolytic circuit and since it has the largest mass connections with it should produce the largest amperage readings. But the core can not play a role in the electro-magnetic circuit.

[resonanceman]

Given that   most of the time all we really need to know  is  how  our coils compare with   our other  coils and  similar  coils that others here have made ............isn't a simple   voltage and   current reading  good enough ?

gary
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No. Not in my mind. How can you say a bottle of milk is good by looking at it? What I mean is a coil of large gauge wire may indeed be able to supply  large amounts of current at a lower voltage, where a smaller wire gauge and more turns will be a higher voltage and lower current. But how can you know the capacity without loading it? Does a voltage comparison make then equal in performance, no, not at all.


So if we have a two 2U6 (9volt transistor batteries connected in series ~100mAHr) which would measure ~18V and three 6V golf cart batteries connected in series ~18v and measure only the voltage, would you be able from the voltage alone be able to tell which had the greater capacity?

RStiffler

I agree  that  we can't tell  much  with just voltage  alone .............but my  question  was   day to day  isn't   just  measuring   voltage AND current  good enough?  ........
I do agree there is times  where  more precision  is needed .
but I am talking  about  taking  basic measuments   off of similar  coils

gary

[resonanceman]

MThompson

Thanks  for   taking  the time to reply

This   kind of discussion  is exactly  what this thread  was intended  for .

You  bring  up  alot of good points.

I am  going to  think about it a while before  I ask  more questions about it .


gary