# Conductor as the secondary through a transformer Core

Discussion in 'The Projects Forum' started by HighVoltage!, Aug 28, 2015.

1. ### HighVoltage! Thread Starter Member

Apr 28, 2014
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I am currently using a transformer to induce current to a cable that has a shield. The cable ends are shorted together (conductor-to-conductor touching)...The shield is open, meaning that they are not touching. Will them being open cause excess voltage? Or the shorting of the conductor "offset" this. Is there a mathematical explanation of this?

2. ### #12 Expert

Nov 30, 2010
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1) No, you aren't. You are not inducing current in a shield that is not connected to anything and you are not creating massive voltages in a shielded core wire that is shorted to itself. The mathematical explanation is that current will not flow in a not-a-circuit and voltage will not build up in a shorted out loop.

3. ### HighVoltage! Thread Starter Member

Apr 28, 2014
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Its sort of like saying you are putting two conductors (Two secondarys) through a transformer one secondary conductor is shorted and the other is open. So your saying the open one wont create dangerous voltages??

4. ### HighVoltage! Thread Starter Member

Apr 28, 2014
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Is it even possible to put two conductors as the secondary of a transformer? Will the "paralleled load" be halved?

5. ### nsaspook AAC Fanatic!

Aug 27, 2009
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Are you using the shield to reduce capacitance coupling to the conductor? Normally you would ground one end of the capacitance shield. If you look at it as a magnetic circuit both wires are parallel to the transformer flux as one coil on top of another. A short in one wire (becoming the same as a massive eddy current loop and assuming the total flux in the transformer remains the same and the transformer does not burn from resistive heating) still leaves a parallel flux path for the induction of voltage on the open shield wire coil.

If you short the filament voltage secondary in a tube high-voltage transformer the plate ac secondary output will still be there. (It might be reduced some due to losses in a real transformer)

6. ### HighVoltage! Thread Starter Member

Apr 28, 2014
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becau

So if I was two use two conductors through a transformer, to reduce capacitance coupling between the two, I simply ground one shield? And from what your saying the "open conductor" will generate voltages.

So the same result will occur if I have ONE conductor (Shielded cable as my secondary output), with the cables conductors touching and completing a loop while the shield is OPEN? What effects the resistance of the loop; the capacitance of the cable itself?

7. ### nsaspook AAC Fanatic!

Aug 27, 2009
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It's to reduce the capacitive coupling between the primary and secondary(s) with shields about the power coil wires but most use a single grounded plate between the primary and secondary coils on a transformer for this shielding.

I'm not exactly sure what the point of your question is. Are you using this cable for a reason or is it just an experiment to see what happens.

Apr 28, 2014
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9. ### HighVoltage! Thread Starter Member

Apr 28, 2014
110
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This is a cable I need to heat up by inducing current through it. As mentioned previously, the cable is shielded; will leaving the shield open while the conductors are connected result is excessive voltages?

Here is the link and slight explanation of what I am trying to do:

http://www.haefely-hipotronics.com/_em-asset/HEAT_CYCLE_DS.pdf

10. ### HighVoltage! Thread Starter Member

Apr 28, 2014
110
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my

I am only using one CT

Apr 28, 2014
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?

12. ### #12 Expert

Nov 30, 2010
17,897
9,316
This hipotronics tester is rated in excess of 1/2 megawatts. There is no coaxial cable involved.
Again, I say, "The full moon is tomorrow."

13. ### nsaspook AAC Fanatic!

Aug 27, 2009
3,634
3,758
The questions you ask make me wonder if you are qualified to handle this type of equipment so I'm out.

14. ### HighVoltage! Thread Starter Member

Apr 28, 2014
110
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It was a never a coaxial cable...I was talking about a 1,500kcm conductor, insulated, copper shield

15. ### HighVoltage! Thread Starter Member

Apr 28, 2014
110
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I dont think your understanding me completely