Ferrite core???

Discussion in 'Digital Photography' started by Dragul, Dec 19, 2003.

  1. Dragul

    Dragul Guest

    Hello again,

    I was wondering if anyone could explain the function and operation of
    a ferrite core on a USB cable.

    Does it have any effect on information going from the camera to a
    computer? I understand from my Dimage A1 manual that it's really only
    necessary when operating the camera remotely, but by the time I'd read
    that, I had already absent-mindedly attached the ferrite core
    according to the diagram.

    I know this a nit-picking kind of question, but I still appreciate any
    advice you can throw my way.

    Oh yeah, please don't try using the email listed here... it doesn't
    work... sorry, I should have mentioned that in my other post.



    Adam.
    Dragul, Dec 19, 2003
    #1
    1. Advertising

  2. Dragul

    Harvey Guest

    Ferrite cores are used around cables for Electromagnetic Interference (EMI)
    suppression. They reduce the extraneous currents in the cables produced by
    large, nearby Radio Frequency fields such as AM radio transmitters, TV
    transmitters, amateur radios, shipboard radios, etc. These currents, while
    not usually strong enough to cause damage, can upset sensitive circuits in
    computer or peripherals and cause data errors. Use of such cores will have
    no effect on transfer of the desired data from the camera to the computer
    via the Universal Serial Bus (USB).

    "Dragul" <> wrote in message
    news:...
    > Hello again,
    >
    > I was wondering if anyone could explain the function and operation of
    > a ferrite core on a USB cable.
    >
    > Does it have any effect on information going from the camera to a
    > computer? I understand from my Dimage A1 manual that it's really only
    > necessary when operating the camera remotely, but by the time I'd read
    > that, I had already absent-mindedly attached the ferrite core
    > according to the diagram.
    >
    > I know this a nit-picking kind of question, but I still appreciate any
    > advice you can throw my way.
    >
    > Oh yeah, please don't try using the email listed here... it doesn't
    > work... sorry, I should have mentioned that in my other post.
    >
    >
    >
    > Adam.
    Harvey, Dec 19, 2003
    #2
    1. Advertising

  3. Some government drone decided we needed these things back in the 80s.
    More useless crap.
    Randall Ainsworth, Dec 19, 2003
    #3
  4. Dragul

    Harvey Guest

    No, the Government drone did not do it. :) AT&T developed Permalloy in
    1928 in response to WWI interrupting the procurement of diamond dies used to
    make fine iron wire. Passing cables through these cores has, for many
    years, been a simple and low cost way to solve many radio frequency
    interference problems.

    "Randall Ainsworth" <> wrote in message
    news:191220030524448275%...
    > Some government drone decided we needed these things back in the 80s.
    > More useless crap.
    Harvey, Dec 19, 2003
    #4
  5. Dragul

    Ralph Mowery Guest

    > Ferrite cores are used around cables for Electromagnetic Interference
    (EMI)
    > suppression. They reduce the extraneous currents in the cables produced

    by
    > large, nearby Radio Frequency fields such as AM radio transmitters, TV
    > transmitters, amateur radios, shipboard radios, etc. These currents,

    while
    > not usually strong enough to cause damage, can upset sensitive circuits in
    > computer or peripherals and cause data errors. Use of such cores will

    have
    > no effect on transfer of the desired data from the camera to the computer
    > via the Universal Serial Bus (USB).


    You started out fine but got it backwards at the end. The core is to
    prevent the computer and other digital devices FROM interfearing WITH
    RECEIVERS. This was noticed with the very first few home computers dating
    back to the time of the Radio Shack Modle 3 atleast.
    There were programs written that you could put your AM radio next to the
    computer and play some tunes in the radio due to this effect.
    Ralph Mowery, Dec 20, 2003
    #5
  6. Dragul

    Harvey Guest

    The original poster said: "I understand from my Dimage A1 manual that it's
    really only
    necessary when operating the camera remotely" That implies that Minolta was
    concerned about the operation of their equipment, not the possible
    interference of their equipment with nearby receivers. Actually it works
    both ways. I have successfully used cores in the past to prevent a very
    nearby radio transmitter from damaging a keyboard.

    "Ralph Mowery" <> wrote in message
    news:...
    > > Ferrite cores are used around cables for Electromagnetic Interference

    > (EMI)
    > > suppression. They reduce the extraneous currents in the cables produced

    > by
    > > large, nearby Radio Frequency fields such as AM radio transmitters, TV
    > > transmitters, amateur radios, shipboard radios, etc. These currents,

    > while
    > > not usually strong enough to cause damage, can upset sensitive circuits

    in
    > > computer or peripherals and cause data errors. Use of such cores will

    > have
    > > no effect on transfer of the desired data from the camera to the

    computer
    > > via the Universal Serial Bus (USB).

    >
    > You started out fine but got it backwards at the end. The core is to
    > prevent the computer and other digital devices FROM interfearing WITH
    > RECEIVERS. This was noticed with the very first few home computers

    dating
    > back to the time of the Radio Shack Modle 3 atleast.
    > There were programs written that you could put your AM radio next to the
    > computer and play some tunes in the radio due to this effect.
    >
    >
    Harvey, Dec 20, 2003
    #6
  7. Dragul

    Ken Weitzel Guest

    Hi...

    Putting a ferrite bead around a wire is virtually identical
    to putting a choke in series with the wire.

    Ain't no RF going through it in either direction. :)

    But fwiw, note that your camera has to guarantee that it
    cause no interference to other operations, and that it has
    no cause of complaint if it recieves interference from
    others.

    In Canada, anyway.

    Take care.

    Ken


    Harvey wrote:
    > The original poster said: "I understand from my Dimage A1 manual that it's
    > really only
    > necessary when operating the camera remotely" That implies that Minolta was
    > concerned about the operation of their equipment, not the possible
    > interference of their equipment with nearby receivers. Actually it works
    > both ways. I have successfully used cores in the past to prevent a very
    > nearby radio transmitter from damaging a keyboard.
    >
    > "Ralph Mowery" <> wrote in message
    > news:...
    >
    >>>Ferrite cores are used around cables for Electromagnetic Interference

    >>
    >>(EMI)
    >>
    >>>suppression. They reduce the extraneous currents in the cables produced

    >>
    >>by
    >>
    >>>large, nearby Radio Frequency fields such as AM radio transmitters, TV
    >>>transmitters, amateur radios, shipboard radios, etc. These currents,

    >>
    >>while
    >>
    >>>not usually strong enough to cause damage, can upset sensitive circuits

    >>

    > in
    >
    >>>computer or peripherals and cause data errors. Use of such cores will

    >>
    >>have
    >>
    >>>no effect on transfer of the desired data from the camera to the

    >>

    > computer
    >
    >>>via the Universal Serial Bus (USB).

    >>
    >>You started out fine but got it backwards at the end. The core is to
    >>prevent the computer and other digital devices FROM interfearing WITH
    >>RECEIVERS. This was noticed with the very first few home computers

    >
    > dating
    >
    >>back to the time of the Radio Shack Modle 3 atleast.
    >>There were programs written that you could put your AM radio next to the
    >>computer and play some tunes in the radio due to this effect.
    >>
    >>

    >
    >
    >
    Ken Weitzel, Dec 20, 2003
    #7
  8. Dragul

    Irwell Guest

    On Fri, 19 Dec 2003 05:24:44 -0800, Randall Ainsworth <> wrote:

    > Some government drone decided we needed these things back in the 80s.
    >More useless crap.


    Not so, "Skin effect" is a very real problem at
    ultra high frequencies.
    Irwell, Dec 20, 2003
    #8
  9. Dragul

    Pard Guest

    On Sat, 20 Dec 2003 04:05:47 GMT, Ken Weitzel <>
    wrote:

    >Hi...
    >
    >Putting a ferrite bead around a wire is virtually identical
    >to putting a choke in series with the wire.
    >
    >Ain't no RF going through it in either direction. :)
    >
    >But fwiw, note that your camera has to guarantee that it
    >cause no interference to other operations, and that it has
    >no cause of complaint if it recieves interference from
    >others.
    >
    >In Canada, anyway.
    >
    >Take care.
    >
    >Ken

    The ferrite bead is put on the wire to assist the manufacturer in
    meeting FCC part 15 requirements for radiated and conducted emissions.
    That it also has the potential for reducing susceptibility of the
    connected devices is just an added bonus, if needed at all.
    Pard, Dec 22, 2003
    #9
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. bigal
    Replies:
    0
    Views:
    1,100
    bigal
    Mar 22, 2006
  2. Brandon

    Fedora Core 3 & Core 4 Password questions

    Brandon, Aug 9, 2005, in forum: Computer Security
    Replies:
    4
    Views:
    1,612
    David
    Aug 15, 2005
  3. Edge
    Replies:
    3
    Views:
    539
  4. Re: What is the use of ferrite core?

    , May 14, 2014, in forum: Digital Photography
    Replies:
    1
    Views:
    62
    nospam
    May 14, 2014
  5. RichA

    Re: What is the use of ferrite core?

    RichA, May 14, 2014, in forum: Digital Photography
    Replies:
    0
    Views:
    70
    RichA
    May 14, 2014
Loading...

Share This Page