component I.D please?

Discussion in 'The Projects Forum' started by Neil Groves, Dec 8, 2011.

  1. Neil Groves

    Thread Starter Member

    Sep 14, 2011
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  2. bertus

    Administrator

    Apr 5, 2008
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  3. Neil Groves

    Thread Starter Member

    Sep 14, 2011
    125
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    Thankyou Bertus, that now leads me to query #2 which is pin 1 isn't an output for this device according to the pin out on the data sheet?

    Neil.
     
  4. sheldons

    Active Member

    Oct 26, 2011
    616
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    it seems there is a mistake on the schematic pin number wise,as pin 1 isnt an output it is in fact the offset null for the 741......the datasheet ive uploaded gives the info for this device
     
  5. Neil Groves

    Thread Starter Member

    Sep 14, 2011
    125
    3
    i was wondering if it was a pin error on the schematic and wanted confirmation, someone suggested checking the schematic against the PCB layout and sure enough, it shows pin 6 as the output.

    thanks guys.

    Neil.
     
  6. Adjuster

    Well-Known Member

    Dec 26, 2010
    2,147
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    And Pin 1 goes nowhere at all, as DC offset nulling is not required here.

    By the look of the guy's haircut though, this circuit must be something like 30 years old. Note the "Ever Ready" PP3 battery.
     
  7. Neil Groves

    Thread Starter Member

    Sep 14, 2011
    125
    3
    i thought as the circuit was in a magazine it had been checked and/or tested prior to publication, obviously not and it's something i need to take into account on future endeavours.

    Yes the circuit is 30 years old appearing in 1981 in everyday electronics or practical electronics i think, i no longer have the original copy though.

    Neil.
     
  8. Audioguru

    New Member

    Dec 20, 2007
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    Why nare you looking at an antique circuit that uses obsolete parts?
    The CA3080 IC has not been made for many years (but somebody might have hoarded some).
     
  9. Adjuster

    Well-Known Member

    Dec 26, 2010
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    The circuit certainly did function, to the extent that such a primitive analogue device could. I think there was a kit made for it (by Maplin?) back in the day. Finished versions of it have been known to turn up on Ebay etc. http://b.matrixsynth.com/2008/08/e-syntom-anlog-synth-tom.html

    Whether you can ever completely trust the details of schematics published in magazines or on the internet is another matter.
    Checking IC pin-outs against manufacturers' datasheets is not a bad idea.
     
  10. Neil Groves

    Thread Starter Member

    Sep 14, 2011
    125
    3
    I ordered 3 ca3080's when i ordered the LM3900's that now i'm not going to use co's the filters are crap lol

    I remembered the Syntom circuit as it was one i wanted to build 30 years ago and never got around to it, just for sentimental reasons i want to build it, maybe along with the other Syn*** circuits down the road.

    edit: oh and co's i can't find any modern equivalent circuits to try ;-)

    Neil.
     
    Last edited: Dec 8, 2011
  11. jameschristian

    Member

    Nov 24, 2011
    58
    0
    I found this a few months ago, and thought it might interest you:
    http://www.megadrum.info/

    Certainly not the same as a trigger, but it's a great interface with a fairly easy build. I am saving up now to build one during the next year, and will post my results once I have something functional.
     
  12. Neil Groves

    Thread Starter Member

    Sep 14, 2011
    125
    3
    I was all excited till i realised it involved computers and programs lol

    thanks anyway

    Neil.
     
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