How can I substitute 2n35 and 2n255 transistors?

Discussion in 'Electronics Resources' started by jkcobain, Jun 8, 2014.

  1. jkcobain

    Thread Starter Member

    Jun 8, 2014
    31
    5
    Hi guys, I'm in the half of engineering, so I don't have much experience yet. So I would appreciate your help to tell me how I can replace those transistors, because I think they are very old.

    If it helps to you, I need them for a pacemaker, this one:

    http://www.seekic.com/uploadfile/ic-circuit/2009720203250264.gif

    If you know an easier way to build a pacemaker (it doesn't have to keep someone alive, of course, it just needs to do a similar function as the real ones do. It is a homework), would be great too.

    Thanks!
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,144
    1,790
    There may exist cross reference lists from JEDEC numbers to NTE. Be aware that NTE components may cost up to 10 times the price of the original component because the are sold as quantity 1 instead of in bulk.

    The second approach is to re-engineer the circuit by developing a set of requirements for the transistors and coming up with a modern equivalent. You might also have trouble with the 1N34A germanium diode as well.
     
  3. Metalmann

    Active Member

    Dec 8, 2012
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    Shouldn't this be in the "Homework Section"?
     
  4. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    2N35; germaniaum NPN, 25v 8mA
    2N255; germanium PNP,15v 3A 20W
    the diode is germanium too...

    And the flashing Neon indicator is probably showing the circuit is from the age before LEDs, or before they were standard. :eek:

    Is there any reason you want to build a 1960's pacemaker circuit?

    If you seriously want to build one why not use a 555 timer, and any common power transistor to drive the coil?
     
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  5. jkcobain

    Thread Starter Member

    Jun 8, 2014
    31
    5
    Thanks! I looked for the list and did find replacements,but you're right, they're way too expensive...
     
  6. jkcobain

    Thread Starter Member

    Jun 8, 2014
    31
    5
    hahaha no special reason, appart that I actually don't know how to build the pacemaker by myself. As I said before, I'm just in half of the career, so I'm still quiet ignorant at some things, specially with analog electronics, cause I haven't taken that subject yet, so I just googled it and found that diagram... :confused:
     
  7. #12

    Expert

    Nov 30, 2010
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    Just click the triangle in the upper, right corner and the moderators will decide.
     
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  8. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    I would "just google it" some more, and find ANOTHER diagram.

    One from this century, or at least the later part of last century.
    ;)
     
  9. jkcobain

    Thread Starter Member

    Jun 8, 2014
    31
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    RichardO likes this.
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