Induction: Questions reg. Coils vs Parallel Conductors

[waterweber]

Needing a bit of help here.

I am trying to transfer an AC signal to a straight conductor via induction.
I am trying to quantify the difference in amount of transferred signal (amps) when the source of the signal is a small coil versus a parallel running straight conductor.
I am thinking its basically the difference between applying the magnetic field over a small area versus a bigger area.
Really looking for the equation that shows the difference and its been too long since I was doing this kind of stuff in college.
Any help is appreciated.

 

[Delta2]

I think you 'll have to use either coil to coil or straight to straight. If you use coil to straight wire then you induce eddy currents in the straight wire which aren't use full at all.

 

[waterweber]

I think you 'll have to use either coil to coil or straight to straight. If you use coil to straight wire then you induce eddy currents in the straight wire which aren't use full at all.

Not worried about eddy currents. This is in relation to utility locators and fairly low frequency AC signals. The eddy currents don't seem to play a role in real world use.

 

[davenn]

This is in relation to utility locators and fairly low frequency AC signals. The eddy currents don't seem to play a role in real world use.

This is not correct
Laminated cores on mains power transformers (50/60Hz) are done for a reason ... to negate the eddy currents generated in the core

 

[waterweber]

Got it.
Bottom line is this works both ways in the real world. I've applied signal using a coil (12" diameter) placed directly above and inline with a conductive line as well as via a parallel running line.
I'm trying to get an idea of how the amount of signal transferred is different using both methods.

 

[davenn]

Got it.
Bottom line is this works both ways in the real world. I've applied signal using a coil (12" diameter) placed directly above and inline with a conductive line as well as via a parallel running line.
I'm trying to get an idea of how the amount of signal transferred is different using both methods.

OK, no probs
You will find large variations with distance and angle between the coil and straight wire

play with variations and take photos in those variations and put up the results on here

I suspect you won't see as much induction between coil and straight wire as you would between 2 coils
Dave

 

[Delta2]

Even if it seems to working , I think what you measure (in the case of coil to straight wire) is some sort of Hall Voltage in the straight wire (which will not be small if the magnetic field from coil is strong) and not the real induced voltage in the straight wire which is really small.