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amtrak IC help — Parallax Forums

amtrak IC help

ArchiverArchiver Posts: 46,084
edited 2003-07-06 16:20 in General Discussion
Hey group

I was recently on a amtrak from Oregon to Washington, it was of the
new "cascade" trains made by talgo.

It had a radio thing built into the seat.
(here is my rendition of it
http://www.angelfire.com/fl5/djx/amtrak.swf)

There were 7 channels of music that you could select with the up/down
buttons and you could alter the volume with the plus/minus.

Im pretty sure how it works is that there are 7 different recievers
for the different stations which are selected with a selective input
IC and then some kind of volume chip to control the volume to your
headphones

Can this be made with some integrated circuits or if I have to use a
stamp?

If anyone has ANY info or suggestions in the construction of this
unit I would love to hear from you

Duncan Fairley
Djdunkman@h...

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-07-06 16:20
    Hi Duncan,

    I think this could be done fairly easily. It will
    require a Stamp for logic control and switch
    monitoring. It will then run the below. Here's my
    suggestions:

    Channel selection:
    Use a Maxim MAX307 (see DigiKey for data sheets) dual
    8 chanel analog multiplexer. With 5 I/O lines, you can
    select 16 lines (8 x L + R) to be directed to 2 common
    outputs. This would allow 8 stereo sources to be
    switched to 2 output lines. These output lines could
    then be buffered and their volume controlled.

    Volume control:
    Use a Maxim DS1867 (see maxim-ic.com for data sheets)
    dual chanel, 256 step, 3 wire serial digital
    potentiometer. This simple device takes the 3 wire
    serial data and adjusts 2 potentiometers. These are
    non-volitile, so they will retain their setting with
    power off.

    With the multiplexer, digital potentiometer, an analog
    power supply, a couple op-amps, and a Stamp with
    switches, you could have a nice little music/analog
    switching system. The beauty of Maxim is that they
    will send you free samples! Add a good Maxim dual
    op-amp to the list and besides the Stamp, power
    supply, and PCA, your project is free.

    Enjoy,
    Dr. Diode

    --- Duncan Fairley <Djdunkman@h...> wrote:
    > Hey group
    >
    > I was recently on a amtrak from Oregon to
    > Washington, it was of the
    > new "cascade" trains made by talgo.
    >
    > It had a radio thing built into the seat.
    > (here is my rendition of it
    > http://www.angelfire.com/fl5/djx/amtrak.swf)
    >
    > There were 7 channels of music that you could select
    > with the up/down
    > buttons and you could alter the volume with the
    > plus/minus.
    >
    > Im pretty sure how it works is that there are 7
    > different recievers
    > for the different stations which are selected with a
    > selective input
    > IC and then some kind of volume chip to control the
    > volume to your
    > headphones
    >
    > Can this be made with some integrated circuits or if
    > I have to use a
    > stamp?
    >
    > If anyone has ANY info or suggestions in the
    > construction of this
    > unit I would love to hear from you
    >
    > Duncan Fairley
    > Djdunkman@h...
    >
    >
    >
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