A Mistake in the All About Circuits Page

Discussion in 'Feedback and Suggestions' started by machan, Apr 15, 2007.

  1. machan

    Thread Starter New Member

    Apr 15, 2007
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  2. recca02

    Senior Member

    Apr 2, 2007
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    the example given on the page does use your formula which didnt get posted. and generally for transformers that formula is used.
    but i believe the formula given on the page is also used. esp for generators.
    we call it as up regulation and down regulation.(dont remember which is which)
     
  3. Dave

    Retired Moderator

    Nov 17, 2003
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    Hi machan,

    The formula on AAC is correct, and hence does not require editing.

    Can I ask where you are getting your version of the equation from? The percentage of voltage regulation is defined in terms of V(no load) and V(full load), I am not sure what V(load) is.

    Edit: In fact there is an error in the worked example further down the page, it should say (9.9V - 9.348V)/9.348V - giving a regulation percentage of 6.8678%

    Dave
     
  4. recca02

    Senior Member

    Apr 2, 2007
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    hi mr. dave,
    first thing first,why cant i see the formula posted by machan?
    now lets get to the problem at hand.
    according to my knowledge the formula given on your page is called
    regulation 'up'


    now this formula:--
    V(no load) - V(full load)
    --------------------
    V(no load)
    is called as regulation 'down'.
    this formula is most commonly used for transformers and regulation if ever specified is always taken as regulation 'down' unless stated otherwise.
    this much i have learned.
    however it is very much possible that these are Indian standards since two books which i used were both by Indian authors.
    ref------electrical technology--by B.L. Theraja & A.K. Theraja.
    until now all regulations i ever calculated while conducting tests on both
    single and 3-phase transformers were regulation down. and fortunately
    all were under 3% :).
    btw
    we used reg up for generators quite frequently.
     
  5. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    recca02,

    I understand where your coming from using regulation up and regulation down. That is from the supplier's view [electric company] to keep the grid within their capabilities.

    The percent of regulation will always be the formula as described in the AAC ebook, when describing the capabilities of the power source.
     
  6. machan

    Thread Starter New Member

    Apr 15, 2007
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    I follow B.L.Thareja for transformers mate. I didn't know that there are Voltage Up and down regulations were there. I saw the formula that corresponds to Up regulation I guess... hence the irony...
     
  7. jrboog

    New Member

    Apr 16, 2007
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    So ? There are going to be upadated text on PN Junctions and all the other lovely semiconductor devices.

    As of now in the EE program at Univeristy of Utah we are covering
    material in this order. (in the ECE 2280 class)
    Amplifier Models
    Op AMPS
    PN Juntions ( diode ) then
    MOSFETS (have no clue why this first) then..
    BJT's (shouldve been after diodes)

    and man let me tell you we have a poor poor teacher that has confused the entire class regarding Mosfets and BJT's... Im looking foward to devouring the text from this site... and hoping I can correctly grasp this stuff.

    Its amazing to me how much easier the EET (non engineerig) books are to read and understand. Plus very little math.... Seems like I may do some reconsidering.

    Thanks for all your hard work. (guys / gals at www.allaboutcircuits.com)
     
  8. Dave

    Retired Moderator

    Nov 17, 2003
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    Thanks recca02, JoeJester and machan for your comments.

    So in conclusion, we are in agreement that the AAC e-book has the correct formula for the Voltage Regulation percentage, and that it is clear in the context in which it is written? (We all agree that the worked example is wrong).

    Is there scope to make the differentiation of regulation 'up' and regulation 'down' as described by recca02 and JoeJester?

    Dave
     
  9. Dave

    Retired Moderator

    Nov 17, 2003
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    Hi jrboog,

    Thanks for your comments. New sections in Volume III are currently undergoing proofreading and will be added to AAC shortly.

    Dave
     
  10. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    Dave,

    I don't think differentiation is needed except at times when some "challenge" what is written.

    During those times, the challenger can provide their source so the members can ascertain the context of the source.

    The language barrier of the members alone causes some problems. The Brits and Yanks use different words. :)
     
  11. Dave

    Retired Moderator

    Nov 17, 2003
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    Thanks for the comments JoeJester. I will proceed with the correction of the worked example, and as far as we are concerned at this moment no further corrections are required to this chapter.

    Further comments and suggestions are welcomed.

    Dave
     
  12. recca02

    Senior Member

    Apr 2, 2007
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    i concur with mr joe
    but i am completely sure of the terminologies used for regulation.
    i also believe the example solved isnt incorrect ,its just isnt in agreement with
    the given formula.
    btw
    a ref book for westinghouse eng
    explained regulation as
    load losses in kw,at rated kva/rated kva
    also i will inform u if i come across something 'substantial'.
     
  13. Dave

    Retired Moderator

    Nov 17, 2003
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    This is where the confusion comes in, the e-book states one formula then proceeds to solve the worked example using a different formula. As far as my understanding is, the stated formula is correct as written however there is a discrepancy with the worked example. I would like to bring the worked example into line with the stated equation, and if we feel there is scope to add further descriptions of other formulae that are applicable in other circumstances then so we can look into this.

    Thanks for the suggested texts, I will see what they have to say on this matter. If you do come across any further information that will be of use please do share.

    Dave
     
  14. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    recca,

    Is that an online reference? What is the title of the reference?
     
  15. recca02

    Senior Member

    Apr 2, 2007
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    hi mr joe,
    if u mean the Westinghouse ref book then i m not sure if there is an online ref
    for that .
    i happen to have a really old book (first edition 1950)
    here are the details of the book i m not sure if the book is available for sale as it was a ref book for eng.
    electrical transmission and distribution reference book
    by -central station engineers of the Westinghouse electric corporation
    east Pittsburgh, Pennsylvania.
    apparently the book has no single author it was written by a team or is an extract from works of different authors.
     
  16. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    recca,


    Central Station Engineers of the Westinghouse Electric Corporation, Electrical Transmission and Distribution Reference Book, 4th Ed., Westinghouse Electric Corporation, East Pittsburgh PA, 1950, no ISBN

    I believe that is your reference book.
     
  17. recca02

    Senior Member

    Apr 2, 2007
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    bingo.
    that indeed is the book,sir.
     
  18. Dcrunkilton

    E-book Co-ordinator

    Jul 31, 2004
    416
    11
    I have made the corrections to the example calculation image in the master copy at ibiblio.org
     
  19. Dcrunkilton

    E-book Co-ordinator

    Jul 31, 2004
    416
    11
    I have updated the copy at ibiblio to correct the example regulation problem.

    In addition, I have recieved massive error corrections to the AC volume. About ten images have been changed, and typos in various chapters. Some of the details are summarized on the appendix A-2 contibutor page. See Michiel van Bolhuis.
     
  20. Dave

    Retired Moderator

    Nov 17, 2003
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    Thanks Dcrunkilton.

    I will inform Rob to run the update script for AAC to bring it into line with the ibiblio.org version.

    Dave
     
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