mid '60's GE SCR hobby projects book

Discussion in 'General Electronics Chat' started by 4-flute, Feb 28, 2013.

  1. 4-flute

    Thread Starter New Member

    Feb 28, 2013
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    Hello to the Forum;

    our group www.veteransinitiative.com is a 501,C-19 non-profit formed thru the American Legion. we are entirely self-funded, no welfare, no crybaby hand-outs. our mission is to give back to our Veterans, especially our most deserving citizen, our DAV. by combining our skills in mfg, we can teach some of these skills in a school for them. some of these skills will include electronic projects, those that have some practical use.
    initially, we are looking for the mid-sixties GE SCR Hobby Circuits book. I remember how interesting the projects were,the staff at GE did a terrific job on it; battery chargers,flashers,lamp dimmers,CDI etc. if the book is not readily found, could some of your members advise where to look for schematics, circuit desriptions?
    thank you for your help.
    May God protect our valiant warriors.
     
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  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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  3. MrChips

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    Oct 2, 2009
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    I think I have that book on my bookshelf. I will have a look in the morning.
     
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  4. THE_RB

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    Is there a PDF of it available? At that age the copyright etc might have expired, it's definitely way past any "commercial" value.
     
  5. davebee

    Well-Known Member

    Oct 22, 2008
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    I've got a copy. I don't really want to sell it or copy the whole thing, but I can help out with copying parts of the book as far as is legal.
     
  6. THE_RB

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    Any stuff in there that is particularly cool?

    Maybe a high amperage car battery charger?
     
  7. davebee

    Well-Known Member

    Oct 22, 2008
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    Here's a battery charger circuit, plus the table of contents.

    My father worked for GE and brought this booklet home when I was a kid, and I've had it ever since. Working out the dates, that was 50 years ago! I feel old.
     
  8. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    Thank you very much for taking the time to post that Davebee! :)

    That battery charger schematic is very similar to a lot of variants on the internet, so it's great to see some original parts values chosen by the experts. :)

    The point when it latches off (stops charging) can be set reliably using the 11v zener and trimpot, however it also claims to turn back on when battery voltage gets low enough and I'm a bit sceptical about that (in case someone is going to build one). Re-turn on can only happen when the battery voltage gets low enough compared to the transformer DC peak voltage to forward bias CR2 and reduce SCR2 anode current below its holding current.

    That is going to require a particular value of transformer DC peak current so I don't think it can be relied upon to "re-start charging when battery voltage drops". It would be have much more honest to say "the circuit is reset when the battery is disconnected, and will start charging again when a battery is reconnected". :)
     
  9. MrChips

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    Oct 2, 2009
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    I have a copy of the GE SCR Manual, Fifth Edition.
    When I have some time I will go through it and look for some interesting projects.

    [​IMG]
     
  10. 4-flute

    Thread Starter New Member

    Feb 28, 2013
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    thanks for the reply to our request. one of our board members thought the CDI project would be a good start. as I remember, the later edition showed both a negative & a positive ground type.
    we are also looking for the late '60' early '70's Ferroxcube catalog. we bought some surplus FC toroids & would like to confirm the core specs. the dims are:
    OD: 1.5"
    ID: .75
    H: .5
    W: .375
    would like to get the core specs: magnetic path L, cross section A, Al/1k turns,
    flux density, materials listed etc (3E, 3E2A, 3B7, 3C8 ?)
    this would be a good class project.
    also, do you know of any plans for a home-built toriod winder, another interesting project. this would combine mechanics & magnetic theory.
    thank you for your interest.
     
  11. 4-flute

    Thread Starter New Member

    Feb 28, 2013
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    thank you for your reply.
    we are also looking for specs on some FerroxCube toroids that we bought surplus. the specs would be in the late '60's & early '70's catalog. the dims are:
    OD: 1.5"
    ID : .75
    H: .50
    Thk: .375

    would like to get the core specs including material (3E, 3E2A, 3B6, 3C8?). also, would like to find a home-built toroid winder dims we could use as a class project.
    thank you for your help.
     
  12. 4-flute

    Thread Starter New Member

    Feb 28, 2013
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    thank you for your reply. we were looking for the CDI schematic as a class project. we have the original schematic & think they showed an update. might have been in the early '70's. there was a problem with the original
    on a un-related subject, we bought some surplus FerroxCube toroids that were mfg in the '60's. the core specs would be in the late '60's & early '70's catalog. the dims are:
    OD : 1.5"
    ID : .75
    W: .375
    Thk: .50

    also looking for the dims to build a simple toroid winder, a nifty class project.
    thank you for your help.
     
  13. 4-flute

    Thread Starter New Member

    Feb 28, 2013
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    thank you for your reply. we thought the GE CDI would be a good class project. we have the original schematic, but there was a problem with it. we think someone showed some improvements in the early 70's.
    also we bought some surplus FerroxCube toroids mfg in the 60's. the dims are:
    OD : 1.5"
    ID : .75
    H : .50
    Thk : .375
    we would like to get the core specs, would be listed in the 60's & 70's catalog. also looking for some dims to construct a home-built toroid winder. that would make a dandy class project.
    thank you for helping us.
     
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