Is this a LED SMD

Discussion in 'General Electronics Chat' started by Seaker, Mar 6, 2013.

  1. Seaker

    Thread Starter Member

    Feb 3, 2013
    I placed an order with a supplier in china for an item and I received this instead. I advised the supplier and they said to keep it and they would resend the correct item. This they did, the question is, does any one know what this item might be? The image is poor due to the items small size.
    If this is a LED strip of SMD's, is this used for automobiles or for standard electrical work.
    Is it another form of SMD (Resister, Diode etc.) ?

    I am hoping that someone might shed some light on this item.

    Thank you in advance.
  2. bance


    Aug 11, 2012
    Apply some constant current, that should shed some light....:)
  3. ErnieM

    AAC Fanatic!

    Apr 24, 2011

    Yeah, they sure do look like SMD LEDs to me. I've used things like that in 0805 (.08" x .05") size as on board indicators. One side had a dot for polarity, though I've seen other with notches.

    What they do varies wildly, but running 5 or 10 mA should light em up and let you see what they do. Then you can try more current, see how bright and hot they get before they burn up.
  4. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    Yep, 0805 SMD LEDs still in the tape.

    You can look at other specs for 0805 LEDs on the internet and get a rough idea of operating current.
  5. Seaker

    Thread Starter Member

    Feb 3, 2013
    Thank you for the replies, based on your comments it appears to be a SMD Led.
    I will try and set up a small testing station and see if I can make one light up.
    From what I have read the voltage will be in the 1.8 to 2.5 range.
    Thanks to everyone.
  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    My Fluke 111 meter has a diode test range step which provides enough voltage and current to forward conduct a diode. Though it seems it is of a vintage preceding common LEDs it does provide just enough drive to dimly light my red SMD LEDs like this so I can assure myself I'm soldering them in correctly.
  7. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    I do that all the time with my Fluke 89IV
  8. takao21203

    Distinguished Member

    Apr 28, 2012
    3V button cell does the trick, have so many around here, some are depleted so absolutely OK, can't damage the LED.

    Depleted 4.5V and 6V lantern battery are good as well for this purpose.

    I even have a resistor on the 4.5V battery.

    So what did OP actually order?? Thread topic is not clear except obviously these are SMD LEDs.
  9. Markd77

    Senior Member

    Sep 7, 2009
    If they don't appear to light up they could be phototransistors or IR LEDs. If they are IR LEDs then you can see them if you look at them on the screen of your camera / phone.