Please help, need info on SMT components

Discussion in 'General Electronics Chat' started by tundrawolf, Feb 8, 2012.

  1. tundrawolf

    Thread Starter New Member

    Feb 8, 2012
    5
    0
    Hello,

    I need help finding out what these components are. They are on a generator voltage regulator. One is clearly visible, the other is missing a small corner.

    The clearly visible unit is large, and is marked 1GZ, 6.C, and has a polarizing stripe.

    The other smaller component has 4 conductors, one large conductor on top, and 3 small conductors on bottom, the center conductor not being used. On the top of this piece there may have been as "S", and on the bottom is marked 5Z.

    Please, I really need help figuring out what these are so I can get my generator back online.

    Here are some pictures:

    [​IMG]

    [​IMG]
     
  2. PaulEE

    Member

    Dec 23, 2011
    423
    32
    Capacitor and either Zener or transistor from the looks of it
     
  3. PaulEE

    Member

    Dec 23, 2011
    423
    32
    Possibly a voltage regulator
     
  4. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,733
    759
    1GZ...could be a diode.

    as for the blown up part, can't say. Try finding the missing peace.
     
  5. PaulEE

    Member

    Dec 23, 2011
    423
    32
    Very true! I saw the stripe and went for cap.

    Try metering it for its diode voltage. If it registers about .7v, diode it may be
     
  6. debe

    Well-Known Member

    Sep 21, 2010
    945
    184
    What sort of generator? Is it 110v or 240V ac with sliprings on the rotor? or 12V/24V DC?
     
  7. BSomer

    Member

    Dec 28, 2011
    433
    106
    I would agree that the one part with the stripe on it is a tantalum capacitor or a diode. If you were to check it with a meter like PaulEE suggested you could find out for certain.

    The problem with the other part is that some of it is gone. I did look through my SMD catalog, but could find nothing that matched the visible code markings. This would lead me to believe that some of the markings may be gone. It looks close to being a SOT-89 or SOT-223 package, though that may not help much. The "5Z" could just be a date code too.
     
  8. BSomer

    Member

    Dec 28, 2011
    433
    106
    You may want to just get a new board if possible. See the areas that I high-lighted in red. Those areas look as though there may be some damage to the traces and pads. The substrate may be damaged as well, which makes repairing the traces more difficult. :(
     
  9. tundrawolf

    Thread Starter New Member

    Feb 8, 2012
    5
    0
    Thank you very much for your help. It is a 120V generator with brushes, I believe it has 12VDC output as well. The field coil is center tapped, and the board uses sensing circuitry to adjust field intensity until the AC output is correct.

    Unfortunately the board is no longer available. I have been thinking about trying to make it "Manually adjustable", or trying to find a voltage regulator that will work. I do not know what sort of DC voltage I would be working with, and it would have to be able to adjust the field coil strength according to the AC output.

    So repairing the board is really my only feasible option.
     
  10. tundrawolf

    Thread Starter New Member

    Feb 8, 2012
    5
    0

    I agree, it looks bad. If I have to run wire from one component to the other I will do that.
     
  11. BSomer

    Member

    Dec 28, 2011
    433
    106
  12. debe

    Well-Known Member

    Sep 21, 2010
    945
    184
    Here is a circuit of a typical AVR for a brush type AC Generator. The Exciter windings on this particular one is 90V ac for Rotor excitation, 25V ac for voltage sensing. To find what the exciter winding voltages are, conect small 12V battery to brushes (Observing polarity) run generator & measure Exciter winding voltages. This should give you the rough voltages that are avalable. This is how i fixed this generator, rebuilding the reg & mounting it externaly in a small plastic box. Its still working.
     
  13. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    I'd guess MOSFET, if one wasn't mounted on those 3 shiny pads that look to fit a TO220 package.

    I don't see it connected to ground, so that sort of rules out voltage regulator.

    MOSFETs also have that extra "cut off substrate lead" in many cases, the disconnected pin is facing down in the picture.

    As far as WHICH MOSFET, I have no clue at all. I'd try to find somebody that has a board like that which still functions, and make some voltage measurements and take some photos.
     
  14. tundrawolf

    Thread Starter New Member

    Feb 8, 2012
    5
    0
    It looks like an SO-223 package. A MOSFET is a good guess... I am going to do my best to make a schematic. I have very limited internet access so I can't reply as much as I would like. But.. If I can figure this out then I am on the fast track to actually making it run right again. Thanks to all of you for your help, I very much appreciate it.
     
  15. tundrawolf

    Thread Starter New Member

    Feb 8, 2012
    5
    0
    I have identified the larger SMT component, it is a diode for sure. But when I input the numbers I don't get anything. Google thinks 1GZ is 1GHz. The reverse voltage is in the .54V range. I spent some time and got this schematic. Maybe it can help us figure out what the mystery components are. I have an intermediate electronics background, some of this is beyond me.

    [​IMG]
     
Loading...