Does magnetic resistance cause electrical resistance in a coil?

[Shadesz]

Suppose you pulse a drive coil creating a magnetic field in opposition of a rotor magnet (to drive it). My question is, due to the magnetic flux that is already surrounding this coil, do you get electrical resistance as it tires to build its own magnetic field? (In other words, Is back EMF stronger?)

[Joit]

Figure the Coil as a straight Wire, then its no.
Figure that the Wires cross eachother, then its yes.
There are only Magnetic Fields, what can disturb or create Resistance to the Magnetic Field.
The only Resistance what then left is from bad leading Material.

[Matthew Jones]

If its just a coil then NO. If its got a core then yes. Because you have to fight saturation of the iron. A north magnets sits on the iron of a coil ready to fire North. The north magnet saturates the iron and creates a south pole through the core. So you fire the coil and it takes time for the current to flow through the coil anyway, but at the same time you now have a counter charge moving in the opposite direction. So you have clear that first.
All that takes time. Counter EMF is not stronger but it slows the process. Anytime you slow the current you have created resistance.

Matt

[mbrownn]

If its just a coil then NO. If its got a core then yes. Because you have to fight saturation of the iron. A north magnets sits on the iron of a coil ready to fire North. The north magnet saturates the iron and creates a south pole through the core. So you fire the coil and it takes time for the current to flow through the coil anyway, but at the same time you now have a counter charge moving in the opposite direction. So you have clear that first.
All that takes time. Counter EMF is not stronger but it slows the process. Anytime you slow the current you have created resistance.

Matt

Will the inductance of a coil in a motor be increased under load?

[Shadesz]

Let me reword it this way, in fact a simple test could tell us.

Connect a bifilar coil in series so the wires create the same magnetic field and send a current through it. Take a reading. Then connect the same bifilar coil in series but this time make it so half of the wire will create a magnetic field in opposition to the original half. Take a reading.

Compare the two readings and you have your answer. If they are the same the answer is there is no electrical resistance due to magnetic flux. If they are different the answer is that there is electrical resistance due to magnetic flux.

Anyone with a free bifilar wound coil care to try this and report back please?

[Allen Burgess]

Magnet flux conductivity.

@Shadesz,

We see lots of experimenters attaching leads to AA battery terminals with tiny round neo magnets. The question seems to be, is there any change in conductivty between the magnetized neodymium and the same unmagnetized alloy? The answer is no! The magnetic field has no effect on the Ohmic resistance of the alloy.

The same holds ture for copper. The presence of a magnetic field has no effect on the wire's Ohmic resistance!

[mbrownn]

I don't think the resistance changes at all but but maybe the impedance does ie inductance, there is a difference. With resistance energy is lost, with inductance energy is stored. I think I am answering my own question here, when coils are opposing such as in a motor, I think the impedance increases, ie inductance.

Impedance is similar to resistance as it restricts low but the big difference is the energy is stored and not lost as heat.

I could have it the wrong way round.

[Iotayodi]

Electronics 102 - Lesson 9 - Impedance versus Resistance

[Shadesz]

Hmm, interesting. So it appears that the situation varies on the circumstance. An ac or pulse dc current is going to have an impedance, whereas a constant dc current only has to consider the resistance.

Is that correct so far?

ps, thanks for the responses

[Joit]

Some of you Guys have some Valid Points, when you say, Magnetism will not effect the Energy what runs through a Coil, Wire.
I connect Magnets most of the Time to my Charge Bateries too, but remember, straight lines, and Energy runs outside around the Wire first, and then saturate it to inside, as far i know. When you push Energy through a Magnet, the EM Forces maybe turns inside to the opposite, or align at the outside, and..

then a Magnetic Amplifier would not work, and it would not affect the Output from a Coil, when you let it run without load and hold a spinning magnetic Rotor beside. But you can indeed that way decrease the Output from a driven Coil.

There we are back at the Hysteris and the Weiss Domains, interesting there, magnetized Domains in the Crystals

[Allen Burgess]

Magnetic amplifiers use the principle of transformer core saturation to act like shut off for a switch. The saturated core won't permit any further magnetization, but conductivity remains constant in the core material.

A magnetic field does not obstruct sunlight. There's no visual distortion viewing over a magnet surface. Light's a different energy. Same goes for electricity.

[Joit]

Well, Magentic Amplifier will work without Core too, using only Air coils, the Cores are helpers, what increase the Capacity? from the Coil at about 2-3x.
I am still not sure, if Electricity is Light, Sound or Vibrations.

[Allen Burgess]

Magnetisem and Electricity.

Magnetisem can be converted into electricity and so can light, but light does not interefere with or help conduct electricity. You've seen enough wireless examples of electricity on youtube. The trasmission of elecrtrc current is not influenced by the presence or abscence of light. Light, electricity and magnetisem are seperate but related forces along with gravity. Now gravity's another thing, and influences the other three forces. Even though they're interchangable, they fail to influence one another. It does nothing to hold a magnet up to a wire conducting electricity. Put a loop in the wire, and it transforms into magetisem. Conversely, magnetisem does nothing to interfere with or help conduct electricity, but pass the field accross the wire and it transforms into it.

[Shadesz]

I don't know about that. The entire point of bemf is magnetism pushing back against an electric current. My question is, is this bemf increased while the coil is already in a magnetic field opposite the one you are trying to create?

[Allen Burgess]

Bemf.

What is BEMF? You 're useing that term, then you turn around and say it's magnetisem, when it's electricity. Magnetisem can't push against electricity. Once again, if you place very powerfull magnets next to a copper wire carrying electricity, the magnetic field has no effect on the electrical current or voltage, or wire resistence.

When current pulses a power coil, the coil generates a magnetic field. The induced magnetic field propels the magnet rotor. When the rotor magnet passes the power coil it generates a current in the coil. It's the induced electrical current that pushes back, not the magnetisem. That's BEMF!