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Wanted: IC's for solder practice

Discussion in 'Datasheets, Manuals or Parts' started by 3v0, Aug 1, 2008.

  1. 3v0

    3v0 Coop Build Coordinator Forum Supporter

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    I need to find unwanted IC's that my class can use to practice soldering. I need at least 50. I would prefer narrow dip chips, not the larger spacing used on 24 pin and larger DIPS.

    I will pay shipping, maybe a bit for the chips.
     
  2. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi 3v0,
    How many would you like, I have quiet a number of the older 74 series 0.3inch pitch.

    They are yours free gratis, just the postage will cover it.:)
     
  3. 3v0

    3v0 Coop Build Coordinator Forum Supporter

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    If you were not in the UK I would jump on the offer. First I need to check out what it would cost to ship them. I would like about 200 of them. That may last me 2 or more years. Depends on how fast the kiddies catch one. Do you have paypal ?

    EDIT: I did not have them do enough practice last year and I spent more time then I wanted finding problems on their projects. I have 3 times the students this year.

    Any idea how may chip/pins per pound are we looking at ?
     
    Last edited: Aug 1, 2008
  4. dave

    Dave New Member

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  5. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi 3v0,

    Just did a quick ic head count, there are qty 210, 74TTL 0.3inch. 14 and 16 pin, plastic case.

    Weighed on kitchen scales, 220gm.

    They are loose, never been used, a quick pop in an ultrasonic cleaner bath, they will be as good as new.

    If you decide to have them, just PM with despatch info.
     
  6. picbits

    picbits Well-Known Member

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    See if you can find a big company (ST / Microchip / National etc) who are in the same country and drop them an email. Make it clear that they don't have to actually work and you might be pleasantly suprised by the response.
     
  7. Speakerguy

    Speakerguy Active Member

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    I have some parts that failed product test from my last job. A whole bunch of 28TSSOP chips. I'm going to use a lot for my own soldering practice but I'll send you the leftovers after I'm done.
     
  8. Speakerguy

    Speakerguy Active Member

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    Also, just go to TI.com and order free samples of their cheapest chips. MAX232 are cheap and they will send you 10. There are other inexpensive chips.
     
  9. gerty

    gerty Member

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    What I do here is have my students remove components from a trashed board to learn desoldering techniques. They then are given a piece (12") of 24 ga solid from some cat5 cable and must solder the wire where the components were. They make a connection, cut it off, move to next hole and do it again. Another thing we do is to make a splice of #12 awg then try to solder it, this shows that you need the proper wattage iron for the size of the wire.
     
  10. jimmythefool

    jimmythefool New Member

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    Thats a very good idea Gerty...
    Soldering a new IC is one thing, but re-working a board is a good skill to learn.
     
  11. Krumlink

    Krumlink New Member

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    Why not get sockets and save the chips?
     
  12. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Try reading the thread title - it's for soldering PRACTICE.
     
  13. 3v0

    3v0 Coop Build Coordinator Forum Supporter

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    Thanks everyone.

    Erlck has donated sufficient DIPs.

    These kids have never touched a soldering iron. I will be happy when they can do a NICE job of soldering DIPs. I rushed it last year and spent too much time tracking down and fixing problems because of it. Basics come first.

    I have a good selection of old MBs with surface mount chips if/when we get to SMD stuff.

    I would rather not use samples for this.
     
  14. futz

    futz Active Member

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    Sockets can be soldered in, same as chips. :p Maybe cheaper than chips, but maybe not.
     
  15. Speakerguy

    Speakerguy Active Member

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    Resistors are also very very very cheap.... you can buy 5,000 carbon film resistors from digikey for $30 + shipping.
     
  16. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Not cheaper than getting old chips for free! :p
     
  17. mvs sarma

    mvs sarma Well-Known Member

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    The whole issue lies in getting chips without pin corrosion. Generally these Chips, unless stocked properly, develop a lot of corrosion and would pose a problem for soldering.
     
  18. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi Sarma,
    The ic's I am planning to send to 3v0 are not corroded, the legs/pins are lightly tarnished, a quick dip in an ultrasonic cleaner bath will remove the tarnish, making them easy to solder.

    When ever components are stored in 'air' the oxygen give a tarnish to the surface.:)
     
  19. mvs sarma

    mvs sarma Well-Known Member

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    Oh, Eric, it was not aimed at you at all please, but a general note. I used to suffer the soldering issues with "tarnished" pins. Now that you tolsd a way out, I would try.
     
  20. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi Sarma,
    No problemo.! :)
     
  21. mneary

    mneary New Member

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    I have a lot of tarnished chips from the 70's; they appear to be silver plated (unique color of the tarnish; could be tin I suppose). What do you use as the reagent in the ultrasonic bath to clean them?

    Also I have a lot of MOSFETs that have been in anti static foam forever (which has become very sticky). Any suggestions for a static safe bath? And where to shop for the ultrasonic unit?

    (I hope this doesn't end up hijacking the thread.) :eek:
     
    Last edited: Aug 8, 2008

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