Results 1 to 10 of 10
Like Tree1Likes
  • 1 Post By jack briggs

Thread: Wire Tension & Inductance

  1. #1
    Senior Member
    Join Date
    Sep 2011
    Location
    Minneapolis
    Posts
    274

    Wire Tension & Inductance

    Understanding that higher tpl results in higher inductance, does wire tension likewise increase inductance with an increase in tension? Or is the other way around?

  2. #2
    Old Timer J M Fahey's Avatar
    Join Date
    Oct 2007
    Location
    Buenos Aires, Argentina
    Posts
    9,322
    Not TPL by itself but actual number of turns.

    Of course, if you fill up a coil form with higher TPL, rising wire tension so you can fit more in same space, then you can fit more turns there, and that is the proper parameter to consider.
    Juan Manuel Fahey

  3. #3
    Member
    Join Date
    Apr 2015
    Posts
    69
    Only marginally, as far as it reduces loop area and turns count.

  4. #4
    Senior Member
    Join Date
    Sep 2011
    Location
    Minneapolis
    Posts
    274
    Thanks. I am puzzling over an original Filtertron that needs repair. The coil is wound so loose it's...surprising. And the inductance is lower than I would have expected. I would a replacement coil but the inductance was much higher so I'm trying to work out what's happening.

  5. #5
    Old Timer J M Fahey's Avatar
    Join Date
    Oct 2007
    Location
    Buenos Aires, Argentina
    Posts
    9,322
    Well, you definitely wound more turns than what was previously there, thatīs for sure.
    Thereīs your difference.
    By the way, your rewind will also be hotter
    Juan Manuel Fahey

  6. #6
    rjb
    rjb is offline
    Old Timer
    Join Date
    Feb 2010
    Location
    Somewhere near Bawlmer, Merlin
    Posts
    2,156

    Look, in the sky! It's a bird! It's a plane! No, it's Kibbitzer Man!

    Quote Originally Posted by jrdamien View Post
    ...I am puzzling over an original Filtertron that needs repair...
    And the inductance is lower than I would have expected.
    You know that the inductance of a coil is inversely proportional to its length, right? So (all else being equal) a tall bobbin will have lower inductance than a short bobbin with the same number of coil turns. But of course the biggest decider, inductance wise, is the relative permeability of the core material.

    Quote Originally Posted by jrdamien View Post
    I would a replacement coil but the inductance was much higher so I'm trying to work out what's happening.
    IIRC, an original Filtertron coil would have about 3000 turns. How many does your replacement have?

    Shalom,
    rb

    EDIT: I see that Juan posted while I was tending the kugel.
    Last edited by rjb; 12-01-2017 at 03:38 AM. Reason: Added parentheses
    In the land of the blind, the one-eyed man is deemed mad.

  7. #7
    Supporting Member mozz's Avatar
    Join Date
    Oct 2015
    Location
    NEPA
    Posts
    396
    "So, all else being equal, a tall bobbin will have lower inductance than a short bobbin with the same number of coil turns.'

    I think you have that backwards. Tall bobbin, more surface area of the core for the wire to contact, higher inductance. A shorter bobbin will be fatter, thus the wire is further away from the core thus less inductance.

  8. #8
    Senior Member jack briggs's Avatar
    Join Date
    Oct 2007
    Location
    Raleigh
    Posts
    250
    Quote Originally Posted by mozz View Post
    "So, all else being equal, a tall bobbin will have lower inductance than a short bobbin with the same number of coil turns.'

    I think you have that backwards. Tall bobbin, more surface area of the core for the wire to contact, higher inductance. A shorter bobbin will be fatter, thus the wire is further away from the core thus less inductance.
    tell that to the P90 bobbin.......

  9. #9
    Supporting Member mozz's Avatar
    Join Date
    Oct 2015
    Location
    NEPA
    Posts
    396
    So, all else being equal.............................

  10. #10
    rjb
    rjb is offline
    Old Timer
    Join Date
    Feb 2010
    Location
    Somewhere near Bawlmer, Merlin
    Posts
    2,156
    Quote Originally Posted by jack briggs View Post
    tell that to the P90 bobbin.......
    Huzzah.

    Quote Originally Posted by mozz View Post
    So, all else being equal.............................
    Yea, I was being intentionally ridiculous.
    But, ignoring that a pickup bobbin isn't really a solenoid, the inductance of a solenoid is really inversely proportional to its length.
    You'll have to ask a physicist to explain why, because I can't. (Not without slogging through some physics text, anyways.)

    Of course, this is all a red herring. I strongly suspect, along with Juan, that OP overwound his replacement coil.

    -rb

    EDIT: Forgot to put this in:
    In the land of the blind, the one-eyed man is deemed mad.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Tension in wire
    By guitar_guy86219 in forum Beginner/ Hobbyist
    Replies: 3
    Last Post: 07-15-2013, 06:21 AM
  2. Understanding Wire Tension
    By Chris_H in forum Beginner/ Hobbyist
    Replies: 10
    Last Post: 05-17-2012, 01:55 PM
  3. Wire tension experiment
    By MrCandy in forum Pickup Makers
    Replies: 11
    Last Post: 09-16-2011, 10:11 AM
  4. Wire Tension and Tone
    By voodoochild in forum Pickup Makers
    Replies: 5
    Last Post: 05-30-2007, 10:00 PM
  5. Applying Tension According to Wire Manufacturer
    By kevinT in forum Pickup Makers
    Replies: 6
    Last Post: 05-03-2007, 03:06 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •