ID? (inductors, I think)

Discussion in 'General Electronics Chat' started by JimG, Mar 29, 2012.

  1. JimG

    Thread Starter Member

    Dec 7, 2009
    53
    0
    Can someone help me identify the two surface mount components inside the red box? I believe they are inductors, but I was not able to confirm this, nor to determine the values, with an internet search.

    They are part of the power supply for a digital temperature controller.

    Thanks in advance.

    Jim
    Kentucky, USA
     
  2. n1ist

    Active Member

    Mar 8, 2009
    171
    16
    I'd guess a diode or zener in a MELF package
    /mike
     
    JimG likes this.
  3. JimG

    Thread Starter Member

    Dec 7, 2009
    53
    0
    Yes, seems to be a MELF package. Thanks for pointing me in that direction.

    But I can't find any diodes that look anything like them. Likewise, I can't find any inductors or resistors that carry a two-bar marking code.

    In circuit, with DMM in ohms mode, one of them acts like a 2K resistor. Across the other one, though, the DMM ohms value is above 1M and continuously rises slowly.

    Guess I might have to take one out and fool around with it.

    Jim
     
  4. praondevou

    AAC Fanatic!

    Jul 9, 2011
    2,936
    488
    In-circuit measuring gives you probably wrong results. You'll have to take them off the board.

    http://www.marsport.org.uk/smd/plasmelf.htm

    Possibly this one? BYM12-150
     
    JimG likes this.
  5. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,754
    760
    My bet is a SMD power resistor or may be a zener diode
     
  6. JimG

    Thread Starter Member

    Dec 7, 2009
    53
    0
    Yes, I'm sure you are correct. But I thought I would take a chance on learning something useful without first removing them :p

    I believe you have solved my mystery! Looks like they are Vishay ultrafast rectifier diodes BYM12-150 / EGL41C SuperRectifiers (150V, 1A). The Vishay datasheet says intended application is high frequency switching power supplies, which is precisely where they appear in my board.

    Many thanks!

    Jim
     
  7. RichD

    New Member

    May 15, 2014
    1
    0
    Hi Jim
    You did a post a while back looking for a variable voltage controlled pot for a circuit that had 120VAC running thru the circuit. Did you ever find a solution to this. I have a similar application.

    Rich
     
Loading...