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    #31
    Letting the sparks, fly, eh, peesoup?

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      #32
      Originally posted by dekoda View Post
      Hi Jimmy! I know because, first, that's standard in the US in residential homes. The power coming into my house has three wires, and if I measure between the outside two wires that are running into my circuit breaker panel, I get 240 volts. If I measure between either one of the outside wires and the middle wire, I get 120 volts.

      Also, if I connect my oscilloscope to one side of the 120, I can see the waveform. If I align the waveform so that it starts at zero, then connect the scope to the other side using the same wire for neutral, the waveform is inverted...that is 180 degrees out of phase.

      The original question was posted in another thread, and I moved it here. I asked Jacki what type of outlet that was in a picture of her. It was different then the outlets we have in the US, and I was curious about it. Of course that also shows my mindset when you have a picture of a beautiful woman, and I notice the outlets...
      Strange system indeed. Just one Q though are you sure they two phases are 180 appart and not 120? The reason being if you have two phases at 180 appart you have no potential difference and hence 0volts when messaured across them (unless my trade theory from 15 years ago has been distored by looking at these lovley ladies here)

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        #33
        tako

        i loved physics! and math. but not chemistry much - boring. loved literature, zoology, space science, which then was mostly van allen belts and what they do to organelles in nucleus of HeLa cells. anyone remember that cell line?. also loved nuclear physics and relativity theory progress. i knew all those early guys. also loved pure math.

        face it: i love to learn stuff...always have. had a double major and 4 minors, couldn't make up my mind..

        once i got knocked across a room and out cold by an amino acid analyzer (old style with slurry tubes, about as big as a car) that had a solvent leak.

        and, gosh, i felt GREAT afterwards. diagnostic test for depression, i guess...

        bragging? naaaaah. just as humble as can be...snork
        d.

        Comment


          #34
          Originally posted by dekoda View Post
          I'm sure this thread will die rather quickly due to lack of interest.
          Well, apparently not, my friend, based on all of these posts! I would have to say that since I've been a member here, this is the most unusually hot thread I've ever come across. I mean that I would think it would only appeal to a very few members. In fact, after reading your introductory post, I actually thought NOBODY would be interested in this. What's next on these boards, a discussion on advanced chemistry?

          Comment


            #35
            Originally posted by laktor View Post
            Well, apparently not, my friend, based on all of these posts! I would have to say that since I've been a member here, this is the most unusually hot thread I've ever come across. I mean that I would think it would only appeal to a very few members. In fact, after reading your introductory post, I actually thought NOBODY would be interested in this. What's next on these boards, a discussion on advanced chemistry?
            Speaking of chemistry, in plants does the transport tissue xylem differ from the phloem tissue by the.....hmmm, got off topic there. Actually, the whole thing got started in another thread when I saw a picture of Jacki in a bathroom. Visible in the picture was a wall outlet that had it's receptical slots in an unusual arrangement.(unusual to me). They were standard in Oz though, but I asked about them.

            I always find it fascinating how diverse the knowledge is in any group of people. Here the knowledge is not only vast, but it comes from all over the world, which also gives us different perspectives on that knowledge. An old timer once told me that even at his age, he finds that he learns at least one new thing every day.

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              #36
              Originally posted by jimmy View Post
              Strange system indeed. Just one Q though are you sure they two phases are 180 appart and not 120? The reason being if you have two phases at 180 appart you have no potential difference and hence 0volts when messaured across them
              That's why the article I linked to in #17 says it's wrong to say "two phase".
              It's more like two copies of a single phase; you can add them together.

              Comment


                #37
                in plants does the

                i think the phloem would transport faster and be more efficienct since IIRC, it's on the inside and protected by the xylum. or am i confusing this with daid pigs for necropsy?

                daid is daid. transport is transport.

                boy, do i need oodles of tea...

                ps - i won't be gambling in vegas either. oppressed by crowds and noise and greed.

                jay-sus. need an IV

                dancer

                Comment


                  #38
                  Originally posted by dekoda View Post
                  Hi Canuck! That green colored sine wave in your post shows you the peak to peak voltage. When we compare AC to DC, then we need to take into account that the AC voltage is not always at it's maximum voltage...it rises from zero volts until it reaches the peak positive voltage (let's say +120 volts for here in the US.) It's only at +120 volts for a tiny amount of time, then it drops in voltage until it reaches the peak minus voltage of -120.

                  If you look at the DC wave form, it's just a straight line that starts at 0 volts, then rapidly rises to it maximum voltage. In order to compare how much work can be done with both voltages, we need to compensate for the AC voltages that are not at 120 volts, so we multiply the peak voltage by .707 to achieve the RMS voltage (Root Mean Square). The RMS voltage is the amount of AC that will do the same amount of the equivalent DC. That is, a 100 peak volt AC circuit can perform the same amount of work as a 70.7 volt DC circuit.

                  It's easy to see that DC is more efficient than AC, but you can't transmit DC over power lines very efficiently. There is line loss due to the resistance of the wire. There is line loss with AC also, but because it's alternating, the loss is a lot less.
                  That was talked about in the link I had, but I didn't want to start getting in to that because I wasn't sure who knew what posting here.

                  Comment


                    #39
                    Originally posted by OlderGuy View Post
                    Luxman said
                    BTW: Basically I'm a technical engineer, so I've learned all this stuff in depth.


                    I have a Ph.D. in Physics [McGill, 1953]
                    OG
                    I am in my first year Electrical Apprenticeship. And it seems like dekota took something a long these lines as well.

                    Comment


                      #40
                      This is an interesting thread dekoda...

                      My house has 5 phases coming into it for a total of 650 volts... it works quite well, I can run lots of stuff at once...

                      Luv Melinda

                      Comment


                        #41
                        As for having PhDs, well COME ON GUYS, TALK YOURSELVES UP HERE, you are all meant to have PhDs right? Of course, PhD stands for Pretty Huge Dick!

                        Sorry, I had to say that one because one of my professors tried that one on me... he said "you know what PhD stands for don't you?" I said no and he said with a grin on his face "Pretty Huge Dick"... he is now in prison.

                        Luv Melinda

                        Comment


                          #42
                          Originally posted by Melinda View Post
                          Sorry, I had to say that one because one of my professors tried that one on me... he said "you know what PhD stands for don't you?" I said no and he said with a grin on his face "Pretty Huge Dick"... he is now in prison.
                          Luv Melinda
                          he'll meet plenty of PhD's in the big house. Yes sireee. He'll make lots of new friends in the showers.

                          Comment


                            #43
                            I have a friend back in Perth doing his PhD... given that it took him several months just to get his project approved by the heads of department, and that his pace of work seems generally laid back and slow, I often rib him about "PhD" standing for Procrastination, Hesitation and Delay

                            Now, back to talking about electrical supply and phases...

                            Comment

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