[SI-LIST] FW: Inductance of wire section

  • From: "McCoy, Bart O." <McCoy.Bart@xxxxxxxx>
  • To: si-list@xxxxxxxxxxxxx
  • Date: Thu, 4 Sep 2003 16:11:16 -0500

Well, you'll probably get a million replies with the same
equation in 50 different forms, but here's one that I use
for a straight-wire of circular cross-section inductance 
calculation that will give you first order effects:


L  =  K * length * [ ln(4*length/Diam) - 0.75 ]

L      = Inductance in nanohenries
D      = Diameter of wire in cm
length = Length of wire in cm
K      = 2


22 Gauge wire....   I'll let you do the calculation given:

20 Gauge AWG  = 0.0813 cm diameter
26 Gauge AWG  = 0.0406 cm diameter


Hope that helps.

   - Bart




-----Original Message-----
From: sdb@xxxxxxxxxx [mailto:sdb@xxxxxxxxxx] 
Sent: Thursday, September 04, 2003 2:53 PM
To: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Inductance of wire section


Hi gang --

Please pardon me if this is a FAQ, but does anybody have a quick
rule-of-thumb for the inductance to expect from a 1 cm length of 22
gauge wire-wrap wire in free space?   Yes, I've searched the web &
looked at a few pages which are far too detailed to be really useful
-- all I want is an order-of-magnitude number, and the websites are
all about calculating the number by integrating Maxwell's equations.  

So far, I've been using a figure of around 360 nH/m, which is the
inductance of a common 50ohm transmission line.  If the real number is
larger or smaller by a factor of 2 to 5 I don't care a lot, but I would
like to make sure that the "rule-of-thumb" number is *not* orders of
magnitude larger or smaller than this.

What rule-of-thumb do you use?

Stuart
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field

List archives are viewable at:     
                //www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages 
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu
  
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field

List archives are viewable at:     
                //www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages 
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu
  

Other related posts: