Help identifying component.

Discussion in 'General Electronics Chat' started by nonsuchpro, Sep 21, 2013.

  1. nonsuchpro

    Thread Starter New Member

    May 31, 2013
    15
    0
    Hi all,

    I aquired a bag of goodies from a friend and neither him or I can figure out what these are. Hence the reason they were in the mix :p
    I looked up the numbers but couldn't find anything. Attached is a pic.

    Any help would be appreciated.
    Thanks in a advance!

    Rob
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,067
    3,837
    They look like radial resistors, (wire wound, ceramic potted) or high voltage capacitors.

    Less likely is the infamous 'fusistor' because those generally look much more crude, like a sand-cast part. Last option could be the 'chemical fuse' like Belfuse/Oneida used to make. I don't remember ever seeing a tall form like you have (same size as those in photo but with two big beefy pins on the long side).

    The part numbers look like Zenith TV part numbers.

    Measure the resistance (and capacitance if you can). The 253 number makes me lean to a 25k ohm resistor or a 25nF capacitor.
     
    Last edited: Sep 21, 2013
    nonsuchpro likes this.
  3. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    They are 12W power resistors (I think).

    The lower code;
    681-12 is 680 ohms 12W
    121-12 is 120 ohms 12W

    I've never seen caps in that package, although if the package is plastic they may be 12v caps.

    If the package is ceramic (which it looks to be?) then power resistors would be my guess.
     
  4. #12

    Expert

    Nov 30, 2010
    16,343
    6,828
    Try to measure them. Without you making any effort at all, we are just guessing.
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,565
    2,379
    There is also they could be LED lights, I notice that the leads are different lengths as often indicates polarity?
    Max.
     
  6. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,067
    3,837
    Yes, nice catch on lead length. we are down to either electrolytic caps, LEDs or ...?

    The 2-77 and 4-77 on the left two pieces could be the date of manufacture. That makes them pretty early LEDs and justification for their crude design. Even though the LED had a 50th anniversary this year, they were only in commercial production since 1974 for indicator lights.

    OP, try a 100 ohm resistor and and two 1.5 volt batteries in series. If that doesn't work, try reversing polarity. I wouldn't try a 9 volt because reverse breakdown is lokely less than 5 volts if you get it backwards. Then again, it may not even be an LED.

    Now that I look at it again, it does look like a window or lens on the end. Could it be a photodiode/photo transistor?
     
  7. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
    The potting on the top. Looks very like the potting used on ceramic high wattage resistor. So I think this is some old resistors dating back to around 1977.
     
  8. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
    784
    I've found caps in similar looking packages a number of times in modems.
     
  9. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    I'm sure they are more likely to be resistors than caps. 12v caps in that size package and low cap value are a bit silly.

    If you look at the end of the middle cap of the 5 you can see it was a axial device inserted into a square tube, which was then filled. The reason for the different lead lengths is because they have turned the axial device into a radial device so one lead will end up longer.

    Anyway a few seconds with a multimeter will clear up a lot, if the O.P. ever returns. ;)
     
  10. nonsuchpro

    Thread Starter New Member

    May 31, 2013
    15
    0
    Thanks for the replies all. They are capacitors! :)

    Unfortunately my LCR broke so I couldn't test capacitance. I did check with a standard multimeter for resistance and if they were diodes. Nothing there so I took them to a buddy's house last night and he was able to check for me. They are 1.2nf and 6.9nf. Not by color tho. There is a green and a black that is 1.2nf and a s green and black 6.9... plus polarization? so odd :confused:

    Anyway, thanks again!
    R.
     
  11. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,565
    2,379
    Longer leads positive.
    Max.
     
  12. #12

    Expert

    Nov 30, 2010
    16,343
    6,828
    You certainly can't tell that from the numbers (unless you know which company marked them). Sears used that system in 1970. All, "in-house" numbers. No way to know except measure them.
     
  13. nonsuchpro

    Thread Starter New Member

    May 31, 2013
    15
    0
    They were measured with my a friends LCR. Different friend from the one who gave them to me.
     
  14. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    Thanks for returning with the info! :)

    To MaxHeadRoom; I really doubt 1.2nF or 6.8nF in that size package would be polarised?
     
  15. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
    784
    I doubt that 6.8nF in any package would be polarised.
     
  16. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,565
    2,379
    That value in that size package could possibly be high voltage?
    If so, often the outer foil etc is often identified for connection to a chassis/power common etc.
    Just as small values are identified with a mark on the common side for the same connection.
    Although non-electrolytic, the schematic symbol for the cap has a polarization symbol To ensure the correct connection for high frequency applications, in this case it could be for high voltage reasons?
    Max.
     
Loading...