Connect with us

Help identifying components

Discussion in 'Electronic Components' started by DaveC, Sep 25, 2010.

Scroll to continue with content
  1. DaveC

    DaveC Guest

    Black diode, smaller than 1Nxxx, green band and green test: "R47".

    Glass diode with yellow band. No other markings.

    Thanks.
     
  2. Josepi

    Josepi Guest

    May be house component marked and only identifiable ny the circuit board
    design people.

    Check for forward voltage drop for Ge or Si, then Zener PIV and most of the
    rest doesn't matter.

    Second unit is probably a Ge diode like 1N34A



    Black diode, smaller than 1Nxxx, green band and green test: "R47".

    Glass diode with yellow band. No other markings.

    Thanks.
     
  3. DaveC

    DaveC Guest

    Black diode, smaller than 1Nxxx, green band and green test: "R47".

    should say 'green text: "R47" '.

    Thanks.
     
  4. DaveC

    DaveC Guest

    Check for forward voltage drop for Ge or Si, then Zener PIV and most of the
    0.58 v-drop.

    How to check for Zener PIV?

    Thanks.
     
  5. DaveC

    DaveC Guest

    What are they in? A little context would help.

    The circuit is in a Hakko 472 desolder station. It controls the switching on
    and off of the vacuum pump motor and vacuum solenoid valve.

    Thanks.
     
  6. Tim Williams

    Tim Williams Guest

    DIAC?

    I have some diodes of similar appearance on RF equipment. I'm guessing
    they are either schottky or varactor. YMMV, could be a manufacturer
    thing.

    Tim
     
  7. DaveC

    DaveC Guest

    Second unit is probably a Ge diode like 1N34A

    Measures 0.59v drop. So: silicon.
     
  8. DaveC

    DaveC Guest

    Does the fact that both show ~ 0.6 v-drop rule out zeners?

    Thanks.
     
  9. DaveC

    DaveC Guest

    Are the vacuum pump and solenoid AC or DC devices?

    AC
    2 triacs: one for the motor, one for the solenoid.
    Not much similarity. The 850 uses a 120vac motor; the 472 uses a 35 vac
    motor. The 850 has no solenoid.

    Thanks.
     
  10. Rich Grise

    Rich Grise Guest

    Variable DC supply, 1 meg resistor, series circuit with diode reverse-
    biased. Watch the diode voltage as you increase the supply voltage.
    When it levels off, you've reached reverse breakdown.

    Hope This Helps!
    Rich
     
  11. DaveC

    DaveC Guest

    Do zeners come in both glass & plastic packages?

    Thanks.
     
  12. Ross Herbert

    Ross Herbert Guest

    :Do zeners come in both glass & plastic packages?
    :
    :Thanks.


    Yes they do..
     
  13. Josepi

    Josepi Guest

    Even without the "variable" this can work. Use a high enough DC voltage.

    There is a method with a scope, resistor and AC supply but it is much more
    complex for a novice (assuming)


    Variable DC supply, 1 meg resistor, series circuit with diode reverse-
    biased. Watch the diode voltage as you increase the supply voltage.
    When it levels off, you've reached reverse breakdown.

    Hope This Helps!
    Rich
     
  14. DaveC

    DaveC Guest

    Even without the "variable" this can work. Use a high enough DC voltage.
    I got the scope, resistor(s). Variac + small transformer = variable AC
    supply.

    So describe away!

    Thanks.
     
  15. Rich Grise

    Rich Grise Guest

    Not simultaneously. ;-P

    Cheers!
    Rich
     
  16. DaveC

    DaveC Guest

    I may have the answer, but No, I can't help you....

    ???
     
  17. Josepi

    Josepi Guest

    hmmmm... Now you are pushing my memory hard!!...LOL

    Let's see.

    Make a series circuit with the resistor (R) at the top and the component at
    the bottom. Feed the whole thing with an AC voltage supply, top to bottom.

    You will need a scope with horizontal input as well as the usual vertical
    input and a floating ground or full differential input somwehere. (you work
    out the logic .. maybe a floating AC voltage supply would be enough)

    Hook the vertical input across the resistor and the horizontal input across
    the component. Maybe the grounds together in the middle of components and
    floating supply are good for that??? Been a few years.

    Now your vertical trace on the scope indicates current (IR drop in the
    resistor).
    The horizontal trace indicates voltage drop across the component.
    You will get the single curve of a component tracer on your scope.

    ***Component curves***
    **shorted = vertical line
    **open = horizontal line
    **resistor same as R = 45 degree line
    **capacitor = circle... me thinks round indicates matching impedance with R
    at 60Hz??
    ** inductor = circle same as cap above??
    **zener no current at lower voltages = horiz. line; no voltage increase at
    higher voltages = vertical line = visible knee at zener voltage - use
    calibrated scales for measurement
    **avalanche diode = horizonatal line with foldback and shows current
    (vertical at higher end)

    Try it! So simple it stinks but is very visible clue. Watch your scope
    grounding.



    I got the scope, resistor(s). Variac + small transformer = variable AC
    supply.

    So describe away!

    Thanks.
     
  18. Tim Williams

    Tim Williams Guest

    What about glass passivated, plastic package diodes? ;o)

    Tim
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-