Re: Solenoid Question

["xeno_tropic" <xeno_tropic@xxxxxxxxx>]

--- In femm@xxxx, "James Stephenson" <j.stephen@xxxx> wrote:
> xeno_tropic,
> 
> Every parameter that you mentioned is critical (wire diameter, core 
diameter/length, # of turns). Obviously you need to keep the device 
specification tolorance in mind before answering these questions. I 
can tell you that small variations in the four variables you 
mentioned can have large consequences from an inductance perspective.
> 
> The inductance of a solonoid is a strong function of the number of 
turns and the core material permeability. The wire diameter has less 
of an effect on the inductance at audio frequencies as long as we 
assume the wire diameter is much smaller than the core diameter.

I appreciate your answer. I will seek coils as close to my original 
as is possible. I am basically using the electromagnets to alter 
human neurological function. The CD contains signals that mimic 
certain characteristics of the electrical signals generated by 
neurons. The wire diameter is fine, and the core diameter is very 
large compared to the wire. As the current source is the audio output 
of a CD player, I assume, as in small audio transformers, that many 
turns of fine wire helps to faithfully reproduce the frequency.
Thanks again.
James