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How would I do this?

  1. Jan 19, 2004 #1
    My car has a knob on the radio to control the volume. How would I make another volume control sp that I could put by the steering wheel so I don't have to reach for the knob on the radio?
     
  2. jcsd
  3. Feb 13, 2004 #2
    Try an electric moter, connect it to the knob, then change the volume by switching the polarity of the moter leads.
     
  4. Feb 13, 2004 #3

    chroot

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    david,

    Is the knob on your radio the kind that can move freely around and around and around in circles forever (an optomechanical knob) or is it the type that can only be turned from one index to another with stops at both ends of the travel (a potentiometer)?

    - Warren
     
  5. Feb 16, 2004 #4
    the knob stops at a certain pt. so yes it is a pot.
     
  6. Feb 16, 2004 #5
    r u for real?[?]
     
  7. Feb 17, 2004 #6
    Fogot to add ADD POWER WHEN YOU WANT THE KNOB TO TURN
    i have a brain fragmentation problem
    i need a defrag
     
  8. Feb 17, 2004 #7
    Why not just run leads through your dash and up your steering column?
    You can attach a pot there.
    Or...
    If you have some kind of aversion to your car looking like a ghetto-fabulous hooptie...
    Buy a new stereo with remote control capabilities and, if it doesn't already come with one, add an aftermarket stalk remote.
     
  9. Feb 17, 2004 #8

    chroot

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    Wire another pot in parallel with the existing one. In the worst case, you might have to fiddle with both knobs to get the volume as high (or as low) as you'd like. I'll think about it and see if I can figure a better way.

    The most common way this is done by car stereo installers is actually rather complex. They add a small box which decodes the buttons pressed on a dash-mounted radio control cluster and translates the commands into infrared pulses, which are then directed at the radio through a small infrared LED.

    In other words, it's just like pressing a button on the head unit's remote control.

    - Warren
     
  10. Feb 17, 2004 #9

    enigma

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    I have no idea how to implement it... just shooting out ideas.

    Could you rig up some sort of bi-stable multivibrator which would trigger (and switch which potentiometer to read) when a specific pot was adjusted? That way it would use the last dial to be touched as the supplier for the voltage level.
     
  11. Feb 21, 2004 #10
    You could try replacing the pot with a digitally controlled pot and using a microcontroller take switch inputs and control the pot. For this you would need some software for the controller and some nice looking dash mounted switches. This is all a lot of hassle, and would take some time to implement properly.

    I would advise buying a head unit that has a remote option. Sony do a good one with steering mounted controls, and its not too expensive. Just watch installing the remote if your steering wheel has an airbag!
     
  12. Feb 21, 2004 #11

    chroot

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    Jeez, just buy a PAC SWI-X and be done with it.

    - Warren
     
  13. Feb 21, 2004 #12
    "Jeez, just buy a PAC SWI-X and be done with it."

    Thats assuming there are already controls on the steering wheel!
     
  14. Feb 22, 2004 #13

    chroot

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    And it's difficult to purchase a couple of momentary switches or something?

    - Warren
     
  15. Feb 22, 2004 #14

    Cliff_J

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    Well a couple switches is no big deal, but getting the wires down the column is another matter. If you're lucky (like a GM car where its the same column as 50 other cars) you can get a new ABS slipring right from the dealer and send your signals down the column in a very OEM fashion. Or else what, something like a coiled phone handset cord?

    Oh, and another way to do this would be to attenuate the radio output. Easy if this is line level going to another stage of amplification, you can buy devices like the MVC (Master Volume Control) from AudioControl that is a fancy attenuation device or just a simple $2 pot. At speaker level, an l-pad (trade term for big honking pot designed for speakers) controlled by an electric motor would work too. So you'd turn up the radio knob and the steering wheel controls how much you cut that back to control volume.

    Cliff
     
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