# Möbius resistor

Discussion in 'General Electronics Chat' started by cmartinez, Jan 29, 2015.

1. ### cmartinez Thread Starter AAC Fanatic!

Jan 17, 2007
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I had never heard of this device. Does any of you know of any practical applications?
And how is one supposed to hook it up, since it doesn't have two extremes?

2. ### #12 Expert

Nov 30, 2010
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Assuming an equal resistance per length, The highest resistance is between any two points that are directly across from each other. That's all I have.

3. ### cmartinez Thread Starter AAC Fanatic!

Jan 17, 2007
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Now I get it... the figure in the article shows how to hook it up. One electrode on one side, and the other directly opposite on the other "side". It also mentions that "... it can resist the flow of electricity without causing magnetic interference at the same time." So I guess it has to be for AC applications... but which ones?

4. ### Lundwall_Paul Member

Oct 18, 2011
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Never heard of one either. After reading up on them. The best thing that I can relate it to is a Non-inductive wire wound resistor. I was hoping that I could find a schematic that uses one. I did read they are used in high frequency applications but the frequency was not mentioned.

5. ### crutschow Expert

Mar 14, 2008
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As discussed here, it's designed to have very little self inductance for use in high frequency circuits (those at which the self inductance of a resistor can be a problem, such as microwave frequencies). It's purpose is the same as conventional non-inductive resistors but is likely better at minimizing the inductance since the current over every surface of the resistive conductor is matched by an equal and opposite current on the opposite side (of course technically a Möbius strip only has one side ).

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6. ### jpanhalt AAC Fanatic!

Jan 18, 2008
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If your twist a round wire, how does it "know" it has been twisted?

John

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7. ### cmartinez Thread Starter AAC Fanatic!

Jan 17, 2007
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Very interesting article, thanks.

8. ### cmartinez Thread Starter AAC Fanatic!

Jan 17, 2007
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Apparently he's referring to the Ayrton-Perry wound resistor that's designed to cancel inductance as well:

• Ayrton Perry winding
Resistors with Ayrton Perry winding are used for the most demanding circuits. This type of winding is similar to the simple winding on a flat former, but in this case two opposite windings are applied. The wires with opposite direction of current are close together, so that the winding is free of self induction. The intersections are on the same potential to have a minor effect on the capacity.
It seems that Vishay manufactures those.

9. ### wayneh Expert

Sep 9, 2010
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I'm nearly round and have certainly been twisted.

10. ### #12 Expert

Nov 30, 2010
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A single round wire doesn't have the necessary insulating layer in the center. That's why it can't tell if it's been twisted into a Mobius loop. Still, I found the simple interpretation of the idea quite humorous. Thanks for the LOL.

11. ### cmartinez Thread Starter AAC Fanatic!

Jan 17, 2007
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Yes, I found it quite humorous too... sorry if my wit seemed a little dry on that one at the time...

His joke actually got me thinking on material properties. I know for a fact that in metallurgy all metals are actually formed out of "grains" (which normally grow when the material is cooled after it was melted and cast), and that those grains share boundaries between themselves that are normally dislocated when, say a wire, suffer plastic distortion. Seldom do the grains themselves actually fracture.
Now, the science of materials has been taking quantum leaps forward in the last few years, and monocrystals are now being used in applications outside of the lab. Take for instance, the SR-71, which is (or was... it's been retired) at least 50 years old. It is my understanding that the blades of its compressor and turbine were manufactured using a monocrystaline steel alloy (not sure if it was steel or other material, though). Anyway, that is what allowed its engines to run at such high RPMs and at such high temperatures. But those are enhancements that manifested in the material's mechanical properties. Maybe @WBahn could elaborate on this... I'm under the impression that he did some maintenance work on those planes.

So what's on my mind at this point is, would a copper monocrystaline wire have different electrical properties than an ordinary one?

Last edited: Jan 30, 2015
12. ### #12 Expert

Nov 30, 2010
16,298
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Quick! Erase that last sentence! The audiophools will be on that term like, "oxygen free" copper.

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13. ### cmartinez Thread Starter AAC Fanatic!

Jan 17, 2007
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I'm laughing here... thanks... now I can hit the sac wearing a smile instead of worrying about paying tomorrow's bills...

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