[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

# Re: [femm] Plots of Je

- To: <femm@yahoogroups.com>
- Subject: Re: [femm] Plots of Je
- From: "Robert Macy" <macy@california.com>
- Date: Wed, 9 Jul 2003 18:29:26 -0700
- Organization: AJM Electronics
- References: <web-49082670@california.com>
- Reply-to: "Robert Macy" <macy@california.com>

    Here is more on my problems plotting Je....

    *IF* the conductor has zero conductivity (as in a wire bundle), then the
    plots of Je and Js+J_eddy all make sense whether the current is defined by
    Js in the materials section or whether it is defined as a total current in
    the circuit section.

    *IF* the conductor has nonzero conductivity (as in a solid wire) *and* the
    current is defined by total current in the circuit section, the answers all
    make sense with the plot of Js+J_eddy being appropriate. However, Je by
    itself goes way wonky inside the conductor. Outside the conductor where
    there is no source current flowing the plots are still correct. Conclusion:
    Only use Js+J_eddy.

    *IF* the conductor has nonzero conductivity (as in a solid wire) *and* the
    current is attempted to be defined as Jsource in the materials section, then
    the analysis really shifts the value of the source current and the results
    are useless. Can't remember about the plots, but the errors make them
    worthless. Conclusion: Always use circuits to define current in a solid
    wire.

    Did I misuse the femm program without knowing it? Is a Jsource for
    conductive wires just incorrect?

    - Robert -

    ----- Original Message -----
    From: robert Macy
    To: femm@yahoogroups.com
    Sent: Tuesday, July 08, 2003 8:17 PM
    Subject: [femm] Plots of Je

    I'm having difficulty interpreting the significance of
    plotting eddy currents.

    I'm plotting eddy currents both in the magnetic material
    and in the conductor's area.

    In the magnetic material where there is no circuit current
    if I plot Je or Js+J_eddy, the plots are identical and look
    as expected.

    In the conductor area if I plot Js+J_eddy, the plots look
    as expected. But when I plot Je by itself, I get
    outlandish values.

    If I plot from the magnetic area into the conductor area
    using only Je, I get identical values to earlier plots
    until the line gets to the conductor, suddenly everything
    goes wonky - making no sense.

    Right now the safe thing to do is to simply only use
    Js+J_eddy for all locations, plot to file, then manually
    remove Js in Excel to see what Je looks like.

    Am I doing something wrong here?

    There is no mention of eddy currents in the manual.

    - Robert -

- Follow-Ups:
  - Re: Plots of Je
    - From: "David Meeker" <dmeeker@ieee.org>

- References:
  - Plots of Je
    - From: "robert Macy" <macy@california.com>

- Prev by Date: Plots of Je
- Next by Date: Brushless DC Motors
- Previous by thread: Plots of Je
- Next by thread: Re: Plots of Je
- Index(es):
  - Date
  - Thread