Effects of magnetic fields on current flow AC or DC??

[aimsbmb]

Hypothetically, what effect will fairly powerful magnets have on current flow in a conductor with potential in millivolt range?
Specifically, DC induced voltage in a human nerve with two magnets adjacent the nerve with magnetic fields overlapping?
I am wondering if there is a possibility this could act as a choke and inhibit current flow? Anyone with a scope to run some tests?
I suffered a spinal cord injury in 2008 Central Cord Syndrome which basically means the insulation was damaged around the
nerves where the injury occurred, so in effect whenever I have elevated electrical activity in my body as it passes this area
it short circuits and lights up 2/3rds of my body with jolts which is quite painful. Anyway, I got thinking if there was someway
to choke or reduce the flow, it may improve the situation. I am an Engineer, but don't really have access to equipment any more
since the injury prevents me from working in the same capacity now. I am certain the voltage is millivolt <100 DC potassium ion
discharge impulse and it is in my neck, so about 1/2" deep. I thought about static elimination, but that I believe would be surface
only. If anyone has any ideas or can test the effects of magnets on a small DC current, it would be greatly appreciated.:angel:

 

[GoldDigger]

An interesting question, but basically an external static (DC or permanent magnet) magnetic field will have no effect on the flow of current except, as in the case of the Hall effect, cause the current to flow preferentially in different areas of a bulk conductor or follow different circuit paths.
A time varying magnetic field (e.g. from AC or moving magnets) will induce voltages that can cause of inhibit current flow.

The physics involved is pretty straightforward, but requires some knowledge of the basic theory of electricity and magnetism to understand and apply properly in complicated situations.

 

[mbrooke]

An interesting question, but basically an external static (DC or permanent magnet) magnetic field will have no effect on the flow of current except, as in the case of the Hall effect, cause the current to flow preferentially in different areas of a bulk conductor or follow different circuit paths.

Hall effect? How does it work?

A time varying magnetic field (e.g. from AC or moving magnets) will induce voltages that can cause of inhibit current flow.

Inductor? So an field that's equal in strength can stop electrons? Much like a ballast restricts current?


I know as much as the OP about this.

 

[GoldDigger]

Hall effect? How does it work?



Inductor? So an field that's equal in strength can stop electrons? Much like a ballast restricts current?


I know as much as the OP about this.

The prime example of the Hall effect involves a thin wide ribbon of conductor.
Apply a magnetic field perpendicular to plane of the ribbon.
Conductors moving along the ribbon are bent by the magnetic field toward one edge of the ribbon.
Since the conductors cannot pile up indefinitely on one side a voltage gradient develops from one edge of the ribbon to the other.
For a constant current the voltage is proportional to the magnetic field.
This is used in DC clamp on ammeters.

 

[mbrooke]

The prime example of the Hall effect involves a thin wide ribbon of conductor.
Apply a magnetic field perpendicular to plane of the ribbon.
Conductors moving along the ribbon are bent by the magnetic field toward one edge of the ribbon.
Since the conductors cannot pile up indefinitely on one side a voltage gradient develops from one edge of the ribbon to the other.
For a constant current the voltage is proportional to the magnetic field.
This is used in DC clamp on ammeters.

Any pics? So its like a sowing bobbin?

 

[GoldDigger]

Any pics? So its like a sowing bobbin?

No, it is a flat ribbon, like a current shunt.
This Wikipedia article is a little long on vector math, but does have a nice illustration.

How this is placed with respect to the clamp jaws of a meter, to measure the field inside the jaws, is a little trickier.

 

[mbrooke]

No, it is a flat ribbon, like a current shunt.
This Wikipedia article is a little long on vector math, but does have a nice illustration.

How this is placed with respect to the clamp jaws of a meter, to measure the field inside the jaws, is a little trickier.

Thanks, A bit easier to grasp. So the hall effect is in essence a DC to DC transformer?

 

[GoldDigger]

Thanks, A bit easier to grasp. So the hall effect is in essence a DC to DC transformer?

Not really. The current is very limited, so I prefer to look at it as a DC current to DC voltage transducer that does not have the voltage drop and power dissipation associated with a shunt.

 

[ghostbuster]

Our group was involved in TDCS and the measurement process several years ago.You may wish to check out the link provided--it may give you some ideas how to neutralize your pain.

http://en.wikipedia.org/wiki/Transcranial_direct-current_stimulation

 

[Tony S]

An interesting question, but basically an external static (DC or permanent magnet) magnetic field will have no effect on the flow of current except, as in the case of the Hall effect, cause the current to flow preferentially in different areas of a bulk conductor or follow different circuit paths.
A time varying magnetic field (e.g. from AC or moving magnets) will induce voltages that can cause of inhibit current flow.

The physics involved is pretty straightforward, but requires some knowledge of the basic theory of electricity and magnetism to understand and apply properly in complicated situations.

Try skin effect.

Hall effect is used in transistor technology.

 

[GoldDigger]

Try skin effect.

Hall effect is used in transistor technology.

As far as I know there is no DC skin effect.
And although most Hall effect sensors are solid state, I would not that it is "used in transistor technology".

 

[Tony S]

As far as I know there is no DC skin effect.
And although most Hall effect sensors are solid state, I would not that it is "used in transistor technology".

Oh well my lecturers must have been wrong about hall effect. Skin effect is an AC phenomenon, hence duplex and quadruplex HV conductors.

BTW
This is the sort of magnet I?m used to, they use pole reversal to release the load.

 

[gar]

150609-2141 EDT

An AC or DC magnetic field does affect a moving electron, or a beam, or a stream of electrons.

Magnetic deflection was the primary means of scaning (deflection) of the electron beam in CRTs larger than about 5". Electrostatic deflection requires excessively large voltages for large screens.

In class we had a problem with a cubic volume where there was a uniform magnetic field in one direction and a uniform electric field in another direction. An electron beam was injected into this volume at a certain location at a specified initial velocity, and perpendicular to the face of the cube. On an opposite face of the cube was a hole not in line with the electron injection location. Our problem was to determine the magnetic and electric field intensities to make the electron beam pass thru the hole on the opposite face. Note; these are both constant intensity fields ( I might call them DC fields.).

Can a DC magnetic field reduce your pain I don't know.

.

 

[aimsbmb]

neurostimulation

neurostimulation

Our group was involved in TDCS and the measurement process several years ago.You may wish to check out the link provided--it may give you some ideas how to neutralize your pain.

http://en.wikipedia.org/wiki/Transcranial_direct-current_stimulation

Not real anxious to have things stuck in me at this point, specially up the spine and the doctors that do this, at least the ones I was seeing, have a limited understanding of my injury that has led to severe setbacks.

 

[aimsbmb]

Thanks

Thanks

150609-2141 EDT

An AC or DC magnetic field does affect a moving electron, or a beam, or a stream of electrons.

Magnetic deflection was the primary means of scaning (deflection) of the electron beam in CRTs larger than about 5". Electrostatic deflection requires excessively large voltages for large screens.

In class we had a problem with a cubic volume where there was a uniform magnetic field in one direction and a uniform electric field in another direction. An electron beam was injected into this volume at a certain location at a specified initial velocity, and perpendicular to the face of the cube. On an opposite face of the cube was a hole not in line with the electron injection location. Our problem was to determine the magnetic and electric field intensities to make the electron beam pass thru the hole on the opposite face. Note; these are both constant intensity fields ( I might call them DC fields.).

Can a DC magnetic field reduce your pain I don't know.

.

Yeah I don't know if it will or not, or if it would even have any effect. I guess what I am hoping for is some way to slow the activity or resist in one direction or create a pseudo depletion region. I know that magnets can be used as noise filters. Just depends on if opposite magnetic poles have any effect on opposite electrical poles? Actually, it seems we generate a measureable electro-magnetic field around our bodies, so it just seems likely that magnets at the very least would have some effect on it? Well anyway, I am going to stick these things on my neck and see if I sense any change/ Thanks for the input.