Image Map Image Map
Page 2 of 2 FirstFirst 12
Results 11 to 17 of 17

Thread: obscure system attached to a fluxgate magnetometer

  1. #11
    Join Date
    May 2005
    Location
    Winnipeg, Manitoba, Canada
    Posts
    447
    Blog Entries
    16

    Default

    Quote Originally Posted by Dwight Elvey View Post
    What uP is it. It looks to be a Motorola. Is it a 6800?
    It was clearly part of a larger system. All the terminal strips make that clear.
    It is missing the flux gate coils. I'd guess they would be on a remote location. One can make flux gates with cores that are easily saturated. RF core often are easily saturated.
    Dwight
    yes a mc6800L

    was all sorts of radio gear up here at one time. from us gov to cdn government to mining and exploration was something els im told.

    what would i be looking for if the coils happen to still be laying around somewhere?

    also im in a remote location at the edge of winter roads where ice road truckers was filmed and king of obsolete reins
    Pegcity bits the home of praire bits and bytes a heritage lost yet not
    Heathkit h89 h77 h11 h10 with some extra bits
    Osborn 1 x2
    pdp8a with asr33 and documentation and software
    GE workmaster with series six PLC and ibm p70 (same as a ge workmaster 2)
    Commodore PC-10 II and other stuff

  2. #12

    Default

    I'm not real sure what you'd look for. I once took apart a dash compass apart to see how it worked. I was a two axis one. It looks like you'd have three separate sensors. What I had was a toroid that had a typical toeoid wind. This is the pulse coil that drives the core in and out of saturation. The fact that the winding goes all around the core means that the magnetic field caused by this winding never leaves the core. It is closed.
    Around this were two windings at right angles. These windings were not toriodial windings. The windings went completely across and around the core. Since my flux gate was both E/W as well as N/S, it had two outside windings.
    The way it works is that the toroidal wing is energized until the core saturates. When this happens, any external field does not see the core as magnetic. The filed lines just go by it as though it was a piece of air. As the current through the toroidial winding reverses, at some point, the core comes out of saturation. The external field now sees the core as a magnetic piece. The field lines all want to pull into the core. The field lines cross the outside winding to get there. This generates a voltage or current depending on the load. This signal has a strength that is related to the angle between the outside turns and the field as well the strength of the field. In my case, the two sense coils were vector added together to produce a compass direction.
    I would suspect the sensors yours used to be three separate core assemblies. Most likely in plastic molded shape with non-magnetic mounts. These would likely have 5 wires. 2 for the sense coil, 2 for the pulse and 1 for the shield. It would surely have some arrow on it indicating the direction of the sense coil to field.
    I hope this makes .
    Dwight

  3. #13
    Join Date
    Jan 2007
    Location
    Pacific Northwest, USA
    Posts
    34,945
    Blog Entries
    18

    Default

    Um, are you okay, Dwight?

  4. #14

    Default

    Quote Originally Posted by Chuck(G) View Post
    Um, are you okay, Dwight?
    I'm never OK. I obviously didn't proof read this one to carefully. Why do you ask? He was asking what the sensors looked like. I thought it might help to know how it worked, to know what to look for.
    Dwight

  5. #15
    Join Date
    Jan 2007
    Location
    Pacific Northwest, USA
    Posts
    34,945
    Blog Entries
    18

    Default

    Oh, it was just the quality of the response that engendered the concern. It wasn't typical of your style.

  6. #16

    Default

    Quote Originally Posted by Chuck(G) View Post
    Oh, it was just the quality of the response that engendered the concern. It wasn't typical of your style.
    I'm quite dyslexic. I usually have to make several passes through my post to fix misspellings and completely wrong words. Sometimes I don't have time to proof read them and I miss a bunch.
    I don't like the small quick reply windows as it is harder to reread through my post but I still use it. I often have to go back and edit post several times.
    This page does better than I can, to describe the sensors:
    https://www.sensorland.com/HowPage071.html
    Still, now days, one can buy cheap solid state ones with all the electronics, except a couple resistors, for a few dollars. It no longer needs the larger boards used in this setup to have really good flux gate sensors.
    Dwight

  7. #17
    Join Date
    May 2005
    Location
    Winnipeg, Manitoba, Canada
    Posts
    447
    Blog Entries
    16

    Default

    Quote Originally Posted by Dwight Elvey View Post
    He was asking what the sensors looked like. I thought it might help to know how it worked, to know what to look for.
    Dwight
    sorta helps neat to learn what they are exactly txs

    havent seen anything remotly like u describe laying around yet
    Pegcity bits the home of praire bits and bytes a heritage lost yet not
    Heathkit h89 h77 h11 h10 with some extra bits
    Osborn 1 x2
    pdp8a with asr33 and documentation and software
    GE workmaster with series six PLC and ibm p70 (same as a ge workmaster 2)
    Commodore PC-10 II and other stuff

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
  •