An unidentified component

Discussion in 'General Electronics Chat' started by yaron3010, Nov 23, 2015.

  1. yaron3010

    Thread Starter New Member

    Nov 23, 2015
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    Hi,

    I have tried to fix an electronic device and inside I found a bed component, I think the component is a type of inductor but I can’t found anywhere the specific type, there is an L mark next to the component and he was soldered where the X is on the circuit, does anyone know what the component type is? Or maybe which other component can I solder instead?


    Thanks
     
  2. Wendy

    Moderator

    Mar 24, 2008
    20,764
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    Looks like an inductor. It should measure as a dead short with an ohmmeter.
     
  3. yaron3010

    Thread Starter New Member

    Nov 23, 2015
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    I know is dead, but I want to replace him and I can't found this component anywhere in the internet, maybe I will just solder 2 separate inductors and see what will happen.
     
  4. RichardO

    Well-Known Member

    May 4, 2013
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    It looks like a transformer to me. If it is then 2 inductors will not work.

    What kind of circuit did the part come out of?
     
  5. alfacliff

    Well-Known Member

    Dec 13, 2013
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    it is a single inductor, there are two heavier wire leads with two smaller wires wrapped around them. the smaller wire is the inductor, the larger is for stronger solder pins. what is marked on it?
     
  6. yaron3010

    Thread Starter New Member

    Nov 23, 2015
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    A few leds connected together and a blower, There is a continuity on two of the pairs? it should be OK if the component is a transformer right?
     
  7. ian field

    Distinguished Member

    Oct 27, 2012
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    They usually fail open circuit or burn up - which would be conspicuous on the plastic sleeving.

    Open circuit is frequently because the wire tails weren't cleaned and tinned prior to wrapping on the pins - close inspection will show whether this is the case.

    Very occasionally they can get shorted turns with no obvious scorching on the sleeving.

    Purely a guess - I'd say maybe somewhere around 10 - 22uH, a substitute inductor would indicate whether there's any sign of life in the rest of the circuit - better to try a higher inductance than a lower one, it won't work properly till you find the right inductance, but you should be able to confirm signs of life.
     
  8. RichardO

    Well-Known Member

    May 4, 2013
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    alphacliff:
    If you look at the picture of the PCB, all 4 leads are connected. I still think it is a transformer.
     
  9. ian field

    Distinguished Member

    Oct 27, 2012
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    The 2nd photo shows a part that clearly has only 2 leads.

    The first photo isn't exactly clear, and the 3rd photo shows 4 pads that all appear to have tracks going somewhere.
     
  10. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    On what basis do you draw that conclusion? -- Very low winding resistance is to be expected - moreover if, as the PCB pads seem to indicate, it is indeed a transformer - it is not necessarily an isolation transformer (i.e. the device may, from a structural, and hence 'DC', standpoint be a multiply tapped winding)

    Best regards
    HP
     
  11. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    Indeed! -- Higher resolution images would be helpful:confused:...
     
  12. ian field

    Distinguished Member

    Oct 27, 2012
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    You could be right - but the 2nd photo looks a lot like a 2 pin inductor.

    Transformers on "cotton reel" bobbins are fairly rare - very rarely CRT TV horizontal driver transformers, and occasionally xenon trigger transformers are made in that style.

    Guessing has probably about reached its limit - time for the TS to describe the application.
     
    Sinus23 and Hypatia's Protege like this.
  13. ian field

    Distinguished Member

    Oct 27, 2012
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    Yesterday I liberated a CO alarm from the Sainsburys battery recycling bin.

    Among the salvage was a "cotton reel" bobbin inductor with 3 pins - its pretty certainly an auto transformer for driving the piezo sounder.

    It would be pointless trying to identify the CT with a DMM, its possible that the Peak LCR meter could tell me if the inductances aren't too low - but I may have to drive it with an oscillator to observe amplitudes and phases on a scope.
     
  14. hp1729

    Well-Known Member

    Nov 23, 2015
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    I have to agree with simple inductor. They don't often go bad but they can get overheated by some other component going bad. Take a close look at capacitors, diodes and transistors in that area. Last resort ... rewind the inductor with new wire.
     
  15. ian field

    Distinguished Member

    Oct 27, 2012
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    If its a basic transformer with isolated primary and secondary, any leakage between the 2 would suggest degrade enamel insulation and probably shorted turns as well.

    But with so little information about the application - it could just as easily be a multi tapped inductor with no isolated windings.
     
  16. hp1729

    Well-Known Member

    Nov 23, 2015
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    Agree on "shorted turns". Unless the circuit was poorly designed inductors and transformers just don't overheat and fail. The bad part is just the symptom. The failed component problem is elsewhere.
     
  17. bwilliams60

    Active Member

    Nov 18, 2012
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    Can we see the rest of the board on both sides and maybe get a better picture of the leads on the component?
     
  18. ian field

    Distinguished Member

    Oct 27, 2012
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    A "cotton reel" bobbin transformer/inductor is pretty hard to saturate - it often betrays that the designer was trying to get away with the smallest cheapest part possible.

    As I mentioned in a previous post; a small number of TV set makers used them for horizontal driver transformers - it was more often than not the cause of failure in those sets.
     
  19. BReeves

    Member

    Nov 24, 2012
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    My guess would also be transformer based on the circuit board but with the info we have guesses are about all anyone can do.
     
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