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Optoisolators: 4N32 vs. NTE3083

Discussion in 'Electronic Basics' started by Jag Man, Oct 22, 2004.

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  1. Jag Man

    Jag Man Guest

    My electronics store sold me the NTE "equivalent" of the 4N32.
    Are these really equivalent?


  2. CFoley1064

    CFoley1064 Guest

    Subject: Optoisolators: 4N32 vs. NTE3083
    Hi, Ed. NTE parts are cross-referenced to standard parts, based on the idea
    that a good part will be a substitute for many different part numbers. I would
    guess that the NTE3083 parts are "house numbered" 4N32s which have been
    post-production tested to cull out the parts that are outliers or are on the
    low side as far as current gain or whatever. In order to be sure, though, you
    basically just have to look at the data sheets:

    A quick scan shows that the NTE part is the same type of part
    (opto-darlington), and should meet or exceed the relevant specs for the 4N32.

    Trust the data sheet. It is your friend.

    Good luck
  3. Jag Man

    Jag Man Guest

    Thanks, Chris.

    As you might guess, this is in relation to the curcuit you posted for me a
    week or so ago.
    I posted some later questions under that thread, but I guess you missed
    Anyway, I guess I'm about ready to start poking things into a project board.
    Only hold up is a back order on the NTE3083 (store had only one) and the

    BTW, in your description of the circuit you seemed to imply that the 4N32
    is non-Darlington, yet the sheets for both it and the 3083 say Darlington.
    Guess it doesn't matter.

    Thanks again.

  4. CFoley1064

    CFoley1064 Guest

    Subject: Re: Optoisolators: 4N32 vs. NTE3083
    Hi, Ed. Sorry -- the AOL newsreader facility is crud. It defaults to deleting
    posts after reading, which causes you to lose track of threads.

    The 4N32 is an optodarlington. It's good for 60 mA continuous, which should be
    enough for your application. The only negatives are speed (unless you take
    care, you're going to have trouble over a few KHz -- not a problem at
    automotive speeds) and that a saturated darlington will have a Vce of about 1V.
    That shouldn't matter for this application, either. For a first cut, I guess
    it's a good choice for what you're doing.

    If you need electronics components and Radio Shack doesn't have them, you might
    want to consider Digi-Key or Mouser as well as NTE. They're all good

    Good luck
  5. Jag Man

    Jag Man Guest


    Regarding the current in the LED portion of the optoDarlingtons,
    I was thinking of 600 ohms, which should give about 20 ma. Is that
    going to work OK?

    Also, I'd like to put in a couple LEDs to give some visual feedback. Would
    it work
    put them between the 2N3904s and GRD?

  6. CFoley1064

    CFoley1064 Guest

    Subject: Re: Optoisolators: 4N32 vs. NTE3083
    20 mA is good for the opto LEDs. That's what I try to shoot for.

    As far as putting some LEDs in the drive loop, how about just putting them on
    the collector side like this (view in fixed font or M$ Notepad):

    .----o A
    VCC VCC |
    | | |
    .-. V~~ |/
    | | VCC VCC VCC ~~ -~~ -|4N32
    | | | | | ___ ~~ | |>
    '-' | | | .-|___|-|<-' |
    | .--o-o--. .---o-----. | LED '----o B
    o--. | 8 4 | | Vdd | ___ |/
    | | | | | "1"o-|___|- -|2N3904 VCC .----o C
    .-. '--o7 | | | 10K | |> | |
    | | | 3o----oCLKEN | .-. | V~~ |/
    | | | | | | 10K| | GND ~~ -~~ -|4N32
    '-' | 555 | | 4017 | | | ___ ~~ | |>
    | .-o6 | .-oCLK | '-' .-|___|-|<-' |
    | | | | | | | | | LED '----o D
    | o-o2 | | | | ___ GND|/
    .-. | | | o-oVss "6"o-|___|- -|2N3904
    | |<-o | 1 5 | | | | 10K | |>
    | | | '--o--o-' | '---------' .-. |
    '-' | | | 10K| | GND
    | | | | | |
    o---' | | '-'
    | GND GND |
    --- GND
    created by Andy´s ASCII-Circuit v1.24.140803 Beta

    This should do the trick.

    Good luck
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