Cool Graphical Method

Discussion in 'General Electronics Chat' started by KL7AJ, Nov 12, 2008.

  1. KL7AJ

    Thread Starter AAC Fanatic!

    Nov 4, 2008
    It's amazing the knowledge you can dredge up when you look for it. I have long wanted a SIMPLE way of calculating complex parallel circuits. I found this method in an ancient manual for my old Pickett Electrolog slide rule. I've never seen this method anywhere else...and now I use it all the time. Rather than explain it here, I'll just post the image from the manual. All comments invited.

  2. scubasteve_911

    AAC Fanatic!

    Dec 27, 2007
    And the nice thing too is that you can know the resultant current or voltage using the complex impedance, so that you can get power factors and other fun stuff

  3. KL7AJ

    Thread Starter AAC Fanatic!

    Nov 4, 2008
    I really think they should require slide rule for engineering courses again. You learn stuff with the slipstick, you just don't learn any other way!

  4. steveb

    Senior Member

    Jul 3, 2008
    I agree! You should change your quote to

    "Real men don't need calculators!"

  5. chilinski

    New Member

    Oct 27, 2008
    Sliderules were a wonderful thing...especially the nice heavy ones that had that ivory patina to them.

    By the way, it appears that Asimov borrowed from Samuel Johnson who said in 1775, "Patriotism is the last refuge of a scoundrel."
  6. awright

    AAC Fanatic!

    Jul 5, 2006
    As one who got an MS in engineering a few years before the first desktop four-function electronic calculator came out, I agree with you about the elegance of the slide rule as a tool. Remember how many engineering wonders were created in the absence of electronic calculators. I recall how my office mates and I gathered around the new portable typewriter-sized wonder in the neighboring engineering firm's office and gasped at how fast the Nixie tubes displayed the result of multiplying two 4 digit numbers.

    However, have you ever tried to get a youth born with an electronic calculator in one hand interested in how a slide rule works? I have, and I might as well have be trying to convince them to use an abacus (or use a manual hand drill).

    (I'm sure that the people who earned their livings doing manual calculations decried the "dependence" of engineers on slide rules when they came into common use, also.)