Announcement

Collapse
No announcement yet.

Comparison of Overhauser and Cesium

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Comparison of Overhauser and Cesium

    Jan,


    I think that using a buffer is a very good idea. This way you spread out the transmit time over the cable so bandwith is reduced. Also, digitizing early seems like a good idea. Digitizing in itself will help reduce errors by making the system less sensitive to noise.


    My only concern is that the more electronics that are on the fish, the more upset I'll be if the cable snaps or the fish gets flooded!


    One idea I had was to put a whole industrial PC down there. This would make life simple, because all kinds of values could be tweaked from the surface, using a remote control program, but suppose things went wrong?! I quickly scrapped that idea!


    I guess what I am trying to say is that I feel the cheaper the fish electronics the better.


    Cheaper doesn't mean less funcional though. That is why I thought of the Ethernet idea. I figured that using a standard part would give us more functionality for less.


    I know virutally nothing about using fiber optic transmissin lines, but I suspect it may require expensive electronics in the fish, and/or an expensive cable.


    If I am wrong then please let me know! My only point is that I want to avoid putting expensive parts where they might get damaged.


    -Bob

  • #2
    Re: Transducer driver/receiver

    Bob,


    The electronics in the fish is not very expensive.


    It extensive use of PIC's will reduce the amount of parts.


    Sending signal over lightpipe is nearly as easy as sending it through a copper wire.


    The main difference is that lightpipe is connected to xmit/receive diode via special connector.


    You cannot just put lightpipe in connector but need special tools for it. (Glassfiber end must be polished and very wel fitted)


    Normally when one orders a length of pipe one can also let them put the connectors on it.


    The major problem I have at the momement is to know what I need to send topside.


    I hope that time between sending and echo + amplitude is enough, but am not sure about it.


    Hope Sture will give answer to this.


    If that is all, I will got for standard RS232 setup.


    There are inexpensive chips using a stripped RS232 protocol which will do the trick.


    I believe that the whole communication electronic will be below $50


    This is for both sides, but without lightpipe and connectors


    At the moment the transducer electronics do not seem to be very expensive (a PIC + some odd bits)


    But this can change depending on what Sture says what we need from the echo.


    I hope I can start the process flow diagram for the electronics next week.


    Then I will start on transducer and start writing the PIC program.


    This will be difficult at first because eventhough I am a programmer I never programmed a PIC before.


    I do not suppose its difficult otherwise they will not sell these things in the quantity they do.


    Regards, Jan

    Comment


    • #3
      Re: Transducer driver/receiver

      Hi Jan,


      If you use a lightpipe are you also going to have power going down the cable? The transducer will want a fair amount of power or at least lots of volts (100 to 1000). You need a tank circuit or something to drive the volts as high as possible. The volts are what make the piezo ceramics expand. The more volts the stronger the wave. I like designing around PICs. It makes the design very flexible. I like every thing I hear so far, I think we’re making progress.


      Tod

      Comment


      • #4
        Re: Transducer driver/receiver

        Tod,


        I have a seperate powersupply in fish.


        I was not planning to have an electrical connection between boat ancd fish.


        All is done via fiber optics.


        I have no idea what voltage I am going to need for transducer, am still gathering information about them.


        If they need several hundred volts than that is no problem (assuming there is no big current involved)


        I will then charge a capacitor with high voltage and discharge it over transducer.


        Regards, Jan

        Comment


        • #5
          Re: ? for carl

          Follow Ups:[/url]

          Comment


          • #6
            Re: ? for carl

            Follow Ups:[/url]

            Comment


            • #7
              Re: ? for carl

              Follow Ups:[/url]

              Comment


              • #8
                Re: gif or jpeg

                Follow Ups:[/url]

                Comment


                • #9
                  Re: gif or jpeg

                  Follow Ups:[/url]

                  Comment


                  • #10
                    Re: gif or jpeg

                    Follow Ups:[/url]

                    Comment


                    • #11
                      Re: Challenging Technical Question about the Radiometer Ferret

                      Follow Ups:[/url]

                      Comment


                      • #12
                        Re: Challenging Technical Question about the Radiometer Ferret

                        Follow Ups:[/url]

                        Comment


                        • #13
                          Re: Challenging Technical Question about the Radiometer Ferret

                          Follow Ups:[/url]

                          Comment


                          • #14
                            Re: Challenging Technical Question about the Radiometer Ferret

                            Follow Ups:[/url]

                            Comment


                            • #15
                              Re: Challenging Technical Question about the Radiometer Ferret

                              Follow Ups:[/url]

                              Comment

                              Working...
                              X