Error on volume 6, chapter 6, P10?

Discussion in 'Feedback and Suggestions' started by Sylverce, May 14, 2008.

  1. Sylverce

    Thread Starter Guest

    http://www.allaboutcircuits.com/vol_6/chpt_6/10.html

    The schematic shows the 10kΩ resistance connected to the base of the PNP transistor and then to ground, whereas the breadboard illustration show it connected to the base of the PNP transistor and then to the collector of said transistor (due to a jumper).

    Is one of them incorrect?
     
  2. Dcrunkilton

    E-book Co-ordinator

    Jul 31, 2004
    416
    11
    Sylverce,

    Thanks for pointing out this discrepancy.

    I think that the 10K resistor should go to ground. The revised image is attached. The bottom wire on the 10K resistor has been moved to the battery center-tap, ground. Once I get agreement tah the breadboard matches the schematic. I will upload it to ibiblio.org.

    Dennis
     
  3. Caveman

    Active Member

    Apr 15, 2008
    471
    0
    You have the bottom of the 10k resistor still connecting to the collector of the PNP, so you've broken the PNP collector node. You should removed the jumper directly below the collector of the PNP. Then you should reconnect the collector node to V-.
     
  4. Dcrunkilton

    E-book Co-ordinator

    Jul 31, 2004
    416
    11
    Thanks for the help caveman.

    Is this better?


    Dennis
     
  5. Caveman

    Active Member

    Apr 15, 2008
    471
    0
    I wasn't totally sure about the schematic, so I read the rest of the experiment page and have noticed that the original intent was that the bottom of the resistor go to V- rather than ground.

    This means that the original breadboard layout is correct but that the schematic is wrong. Also note that the same image, http://sub.allaboutcircuits.com/images/05320.png, is also shown at the bottom of the screen, so both need to be changed.
     
  6. Dcrunkilton

    E-book Co-ordinator

    Jul 31, 2004
    416
    11
    Caveman,

    After reading the text, I agree with you. The 053021.png breadboard goes back to the original drawing and the attachment shows the 05320.png schematic changed in accordance with your advice.

    Once I get confirmation of this change, I will update at ibiblio.

    Dennis
     
    Last edited: May 14, 2008
  7. Caveman

    Active Member

    Apr 15, 2008
    471
    0
    Looks good.
     
  8. Sylverce

    New Member

    May 14, 2008
    1
    0
    Just thought I'd mention this.

    Today I built the circuit in question (the corrected version) and it worked perfectly.

    Thank you for your quick responses.
     
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