Basic Transistor question for hobbyist

Discussion in 'General Electronics Chat' started by n9jcv, Apr 14, 2016.

  1. n9jcv

    Thread Starter New Member

    Apr 14, 2016
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    Hello everyone, I have been reading Understanding Basic Electronics 1st edition by Larry Wolfgang. Page 27-5 has the below diagram. I am confused, because either my understanding is wrong (most likely) or the book has an error.

    The diagram shows a PNP transistor. I can confirm it is a PNP because the diode/triangle points in. What is confusing to me, is they have labeled the diode leg as the Collector. In all other references I see of PNP, the diode leg is a Emitter. Is the book in fact incorrect?

    trans2_641x456.jpg
     
  2. dl324

    Distinguished Member

    Mar 30, 2015
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    Welcome to AAC!

    You are correct. The emitter and collector are labeled incorrectly. There may be a later edition with a correction.
     
  3. n9jcv

    Thread Starter New Member

    Apr 14, 2016
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    thank you, my head was spinning all night thinking I was not fully understanding something. at this point I am glad the book is incorrect :) I just hope the rest of the book is correct.
     
  4. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    You are correct,,the arrow should be on the emitter at the bottom positive terminal,
     
  5. dl324

    Distinguished Member

    Mar 30, 2015
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    Does the biasing description make sense to you? Unfortunately, both batteries in that figure are backwards.
     
  6. MrChips

    Moderator

    Oct 2, 2009
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    No, no. The two batteries are correct. The labels Collector and Emitter are in the right place. PNP label is correct.
    It is the arrow on the transistor is in the wrong place. The arrow should be on the emitter.

    trans2_corrected.jpg
     
    wayneh likes this.
  7. dl324

    Distinguished Member

    Mar 30, 2015
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    There's less wrong with it if you look at it from that perspective. I prefer to have schematics flow from left-to-right and top-to-bottom.
     
  8. Tonyr1084

    Active Member

    Sep 24, 2015
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    I agree. I really had to spend time looking at that one (once corrected). Before the correction my head was spinning too.
     
  9. wayneh

    Expert

    Sep 9, 2010
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    That'd make a great test question, if one were a sick and twisted teacher.
     
  10. MrChips

    Moderator

    Oct 2, 2009
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    trans2_corrected.jpg

    The first transistor circuits I ever worked with were PNP Ge, OC44, OC45, OC71 and OC72 in the Philips Electronics Engineer kit.
    All the circuits were drawn that way with -Vsupply at the top and +Vsupply connected to GND at the bottom.

    That makes the view and circuit topology consistent with the more popular use of NPN Si transistors.
     
    recklessrog likes this.
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