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Parallel Voltages and Current.

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  • #16
    OK, I came here for the bikinis. Where are the bikinis?
    If it still won't get loud enough, it's probably broken. - Steve Conner
    If the thing works, stop fixing it. - Enzo
    We need more chaos in music, in art... I'm here to make it. - Justin Thomas
    MANY things in human experience can be easily differentiated, yet *impossible* to express as a measurement. - Juan Fahey

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    • #17
      Kirchoff's first, then you can have your bikinis. How can you have any pudding if you don't eat yer meat?

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      • #18
        Originally posted by eschertron View Post
        OK, I came here for the bikinis. Where are the bikinis?
        Yep, one of those rare occasions when I wonder if having an adblocker means I'm missing out.
        Originally posted by Enzo
        I have a sign in my shop that says, "Never think up reasons not to check something."


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        • #19
          Originally posted by HaroldBrooks View Post
          Yes, you are correct. Not sure what the heck I was thinking about, I must have been tired the last time I layed my hands on it ! Just measured the voltage on the pin side of the resistor and is all makes sense now, as the run from the capacitor (not from the B+) is the same, no mystery anymore.

          But hey, similar hypothetical question, if I took two separate voltages from the same power supply, let's say one was roughly B+ around 350vdc, and the other had been dropped by a resistor to let's say 250vdc what would I get if I connected them together ? would the higher voltage just "Win out" ? I've never seen that but I wonder what would be the result. Also if current were drawn from that connection would it be stable, as in different than either the line with the resistor or the one without ?

          It would be nice if I got a book on this stuff ! any recommendations would be welcomed. I now have time to study more than before.

          Thanks for everyone's help so far !


          P.S. one last thing, I keep seeing ads for "2019 hottest Bikinis" coming up on this website, is this a feature of being involved in electronics, or something related to the question of voltage perhaps ?
          We now know what else you've searching on your computer.


          nosaj
          soldering stuff that's broken, breaking stuff that works, Yeah!

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          • #20
            Originally posted by Mick Bailey View Post
            Kirchoff's first, then you can have your bikinis. How can you have any pudding if you don't eat yer meat?
            Leave the kid alone!

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            • #21
              Originally posted by Mick Bailey View Post
              Kirchoff's first, then you can have your bikinis. How can you have any pudding if you don't eat yer meat?
              Floyd, my favorite ! Almost as good as the popup ads !

              Now I can see why the call some ads pop ups.

              Thanks for the excellent explanations as usual regarding voltages and resistance. For some reason I've run out of amps to work on... This is a serious situation and I sick of reading about covid 19, the end of the economy, politics, or meaningless vids on youtube. Talk about wasting time !

              I need to start working on something new ! I had the idea for a home made Leslie amplifier.

              Anyone know how they get the signal to the spinning horns ? do they use brushes ? I have zero experience with Leslies, other than seeing and hearing them being used on a Hammond.

              I just hijacked my own thread.
              " Things change, not always for the better. " - Leo_Gnardo

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              • #22
                The horn has a compression driver mounted on that upper "floor" pointing up. The rotary horn rotates above that. The horn is Y shaped, but only one side is the real horn, the other side is a dummy just to balance the rotor. There is no moving speaker to get a signal to up there. only thing moving is the horn itself.

                Down below, there is another inner "floor". The woofer is mounted over a hole facing down. Below that hole is a drum with an angled board in it. The drum rotates. The sound from the woofer blows down and bounces out sideways off the angled board. That swirls the sound around. SO again, there is no moving speaker top run wires to, just a moving sound reflector.

                So most common Leslie speakers have no moving contact issues, because there are none.

                But there are a few Leslies that have smaller speakers that do move. I had one with a 6x9 speaker on a drum. I am not sure how many models are affected. They used something called a Mercotac. It was basically like a ball bearing spindle, one on each end of the spinning drum. The drum end of the mercotacs could spin while the other end was anchored to the frame. The mercotac carried current through the center.

                Mercotac is still around:
                http://www.mercotac.com/

                Click image for larger version

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                Education is what you're left with after you have forgotten what you have learned.

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                • #23
                  That looks like a mercury commutator - now banned in the EU at least along with everything else that contains mercury. I've often thought of adding a Leslie-type speaker to my list of projects. One thing to consider is a keyboard has a much lower range than a guitar so maybe the enclosure and drivers could be smaller. There are a few compact units made over the years that could serve as a model - I don't know how successful a Leslie would scale down, though and still retain enough characteristics to make it worthwhile.

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                  • #24
                    Originally posted by HaroldBrooks View Post
                    Floyd, my favorite ! Almost as good as the popup ads !

                    Now I can see why the call some ads pop ups.

                    Thanks for the excellent explanations as usual regarding voltages and resistance. For some reason I've run out of amps to work on... This is a serious situation and I sick of reading about covid 19, the end of the economy, politics, or meaningless vids on youtube. Talk about wasting time !

                    I need to start working on something new ! I had the idea for a home made Leslie amplifier.

                    Anyone know how they get the signal to the spinning horns ? do they use brushes ? I have zero experience with Leslies, other than seeing and hearing them being used on a Hammond.

                    I just hijacked my own thread.
                    Check your PM's
                    nosaj
                    soldering stuff that's broken, breaking stuff that works, Yeah!

                    Comment


                    • #25
                      Well it is called a MERCotac.
                      Education is what you're left with after you have forgotten what you have learned.

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                      • #26
                        Motion Sound still makes a spinning horn based on the Leslie.

                        Originally posted by Enzo
                        I have a sign in my shop that says, "Never think up reasons not to check something."


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                        • #27
                          Originally posted by g1 View Post
                          Motion Sound still makes a spinning horn based on the Leslie.

                          Thanks g1 This is great ! One thing I am concerned about though, I heard in the past some tube amp driven rotary setups, and as you might expect, they sound a bit warmer than the solid state variety. But as with all things in life, you generally have to accept some compromise. I could use that unit with a wet / dry stage arrangement, or perhaps mike a tube amp and put it though the rotary. I have to get my hands on some of this stuff and experiment before I plunk down cash.

                          Two classic killer songs in particular showed me years ago how absolutely cool a guitar can sound through a rotary setup, one is the lead solo to Led Zepplin's " Good Times Bad Times @ 1:28 "
                          https://www.youtube.com/watch?v=lsZG7n7ries

                          The other is David Gilmour's solo on Pink Floyd's " Dogs @ 1:50 "
                          https://www.youtube.com/watch?v=qiaF4kuxJco

                          Gilmour uses the rotary mixed in and blended with one of his amps (and probably a few other studio tricks), so the effect is more subtle but outrageous in the way it "colors" the frequency of certain notes. Stunning.
                          You can try all you want to achieve that tone with any electronic time delay or delays, and you can get close (I've done it), but as they say "No Cigar" in the end.

                          You need the physical Doppler effect after all is said and done. It's subtle, but like a chef's secret sauce, it's undeniable to the discerning ear if that's what you are looking for.
                          Last edited by HaroldBrooks; 05-09-2020, 11:45 PM.
                          " Things change, not always for the better. " - Leo_Gnardo

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