# Re: mathematics

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From: 	DamDeName-at-aol-dot-com[SMTP:DamDeName-at-aol-dot-com]
Sent: 	Sunday, September 07, 1997 3:10 AM
To: 	tesla-at-pupman-dot-com
Subject: 	Re: mathematics

Hi Kevin,

One handy-dandy formula for single layer coils is :

L= (N x A)^2 / 9A + 10B

where: L   is inductance in microheneries
N   is the number of turns
A   is  the mean radius of the coil in inches
B   is the  length of the coil in inches

The above formula ---- re-arranged as follows --- will determine the
number of turns for a given inductance--------------

N = the square root of L(9A  +  10B )/A

According to the scuttlebutt  the above are accurate to 1%

Have fun ,
Sandy

In a message dated 97-09-06 01:24:18 EDT, you write:

<< Now that I have a functioning coil, I would like to begin to read in on
the theory and especially the mathematics.  Is there a single good book
that can help me, or maybe a few?  I tried the library but found nothing
about coils.  I am probably going to try the local university next.

Also, would anyone happen to know a formula for calculating the
inductance of a choke, taking into account the form shape and size, the
wire gauge, and the number of turns?

thanks,
kevin >>

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